International Nuclear Information System (INIS)
Safranek, J.; Lee, M.
1994-02-01
The quadrupole strengths, beam position monitor (BPM) gains, and orbit correction magnet strengths were adjusted in a computer model of the NSLS X-Ray ring in order to best fit the model orbit response matrix to the measured matrix. The model matrix was fit tot the 4320 data points in the measured matrix with an rms difference of only 2 to 3 microns, which is due primarily to noise in the BPM measurements. The strengths of the 56 individual quadrupoles in the X-Ray ring were determined to an accuracy of about 0.2%. The BPM and orbit corrector calibrations were also accurately determined. A through analysis of both random and systematic errors is included
Orbit Classification of Qutrit via the Gram Matrix
International Nuclear Information System (INIS)
Tay, B. A.; Zainuddin, Hishamuddin
2008-01-01
We classify the orbits generated by unitary transformation on the density matrices of the three-state quantum systems (qutrits) via the Gram matrix. The Gram matrix is a real symmetric matrix formed from the Hilbert–Schmidt scalar products of the vectors lying in the tangent space to the orbits. The rank of the Gram matrix determines the dimensions of the orbits, which fall into three classes for qutrits. (general)
Theory of orbital magnetoelectric response
International Nuclear Information System (INIS)
Malashevich, Andrei; Souza, Ivo; Coh, Sinisa; Vanderbilt, David
2010-01-01
We extend the recently developed theory of bulk orbital magnetization to finite electric fields, and use it to calculate the orbital magnetoelectric (ME) response of periodic insulators. Working in the independent-particle framework, we find that the finite-field orbital magnetization can be written as a sum of three gauge-invariant contributions, one of which has no counterpart at zero field. The extra contribution is collinear with and explicitly dependent on the electric field. The expression for the orbital magnetization is suitable for first-principles implementations, allowing one to calculate the ME response coefficients by numerical differentiation. Alternatively, perturbation-theory techniques may be used, and for that purpose we derive an expression directly for the linear ME tensor by taking the first field-derivative analytically. Two types of terms are obtained. One, the 'Chern-Simons' term, depends only on the unperturbed occupied orbitals and is purely isotropic. The other, 'Kubo' terms, involve the first-order change in the orbitals and give isotropic as well as anisotropic contributions to the response. In ordinary ME insulators all terms are generally present, while in strong Z 2 topological insulators only the Chern-Simons term is allowed, and is quantized. In order to validate the theory, we have calculated under periodic boundary conditions the linear ME susceptibility for a 3D tight-binding model of an ordinary ME insulator, using both the finite-field and perturbation-theory expressions. The results are in excellent agreement with calculations on bounded samples.
Transition matrices and orbitals from reduced density matrix theory
Energy Technology Data Exchange (ETDEWEB)
Etienne, Thibaud [Université de Lorraine – Nancy, Théorie-Modélisation-Simulation, SRSMC, Boulevard des Aiguillettes 54506, Vandoeuvre-lès-Nancy (France); CNRS, Théorie-Modélisation-Simulation, SRSMC, Boulevard des Aiguillettes 54506, Vandoeuvre-lès-Nancy (France); Unité de Chimie Physique Théorique et Structurale, Université de Namur, Rue de Bruxelles 61, 5000 Namur (Belgium)
2015-06-28
In this contribution, we report two different methodologies for characterizing the electronic structure reorganization occurring when a chromophore undergoes an electronic transition. For the first method, we start by setting the theoretical background necessary to the reinterpretation through simple tensor analysis of (i) the transition density matrix and (ii) the natural transition orbitals in the scope of reduced density matrix theory. This novel interpretation is made more clear thanks to a short compendium of the one-particle reduced density matrix theory in a Fock space. The formalism is further applied to two different classes of excited states calculation methods, both requiring a single-determinant reference, that express an excited state as a hole-particle mono-excited configurations expansion, to which particle-hole correlation is coupled (time-dependent Hartree-Fock/time-dependent density functional theory) or not (configuration interaction single/Tamm-Dancoff approximation). For the second methodology presented in this paper, we introduce a novel and complementary concept related to electronic transitions with the canonical transition density matrix and the canonical transition orbitals. Their expression actually reflects the electronic cloud polarisation in the orbital space with a decomposition based on the actual contribution of one-particle excitations from occupied canonical orbitals to virtual ones. This approach validates our novel interpretation of the transition density matrix elements in terms of the Euclidean norm of elementary transition vectors in a linear tensor space. A proper use of these new concepts leads to the conclusion that despite the different principles underlying their construction, they provide two equivalent excited states topological analyses. This connexion is evidenced through simple illustrations of (in)organic dyes electronic transitions analysis.
Coulomb matrix elements in multi-orbital Hubbard models.
Bünemann, Jörg; Gebhard, Florian
2017-04-26
Coulomb matrix elements are needed in all studies in solid-state theory that are based on Hubbard-type multi-orbital models. Due to symmetries, the matrix elements are not independent. We determine a set of independent Coulomb parameters for a d-shell and an f-shell and all point groups with up to 16 elements (O h , O, T d , T h , D 6h , and D 4h ). Furthermore, we express all other matrix elements as a function of the independent Coulomb parameters. Apart from the solution of the general point-group problem we investigate in detail the spherical approximation and first-order corrections to the spherical approximation.
An Empirical State Error Covariance Matrix Orbit Determination Example
Frisbee, Joseph H., Jr.
2015-01-01
is suspect. In its most straight forward form, the technique only requires supplemental calculations to be added to existing batch estimation algorithms. In the current problem being studied a truth model making use of gravity with spherical, J2 and J4 terms plus a standard exponential type atmosphere with simple diurnal and random walk components is used. The ability of the empirical state error covariance matrix to account for errors is investigated under four scenarios during orbit estimation. These scenarios are: exact modeling under known measurement errors, exact modeling under corrupted measurement errors, inexact modeling under known measurement errors, and inexact modeling under corrupted measurement errors. For this problem a simple analog of a distributed space surveillance network is used. The sensors in this network make only range measurements and with simple normally distributed measurement errors. The sensors are assumed to have full horizon to horizon viewing at any azimuth. For definiteness, an orbit at the approximate altitude and inclination of the International Space Station is used for the study. The comparison analyses of the data involve only total vectors. No investigation of specific orbital elements is undertaken. The total vector analyses will look at the chisquare values of the error in the difference between the estimated state and the true modeled state using both the empirical and theoretical error covariance matrices for each of scenario.
Hexagonal response matrix using symmetries
International Nuclear Information System (INIS)
Gotoh, Y.
1991-01-01
A response matrix for use in core calculations for nuclear reactors with hexagonal fuel assemblies is presented. It is based on the incoming currents averaged over the half-surface of a hexagonal node by applying symmetry theory. The boundary conditions of the incoming currents on the half-surface of the node are expressed by a complete set of orthogonal vectors which are constructed from symmetrized functions. The expansion coefficients of the functions are determined by the boundary conditions of incoming currents. (author)
Response matrix method for large LMFBR analysis
International Nuclear Information System (INIS)
King, M.J.
1977-06-01
The feasibility of using response matrix techniques for computational models of large LMFBRs is examined. Since finite-difference methods based on diffusion theory have generally found a place in fast-reactor codes, a brief review of their general matrix foundation is given first in order to contrast it to the general strategy of response matrix methods. Then, in order to present the general method of response matrix technique, two illustrative examples are given. Matrix algorithms arising in the application to large LMFBRs are discussed, and the potential of the response matrix method is explored for a variety of computational problems. Principal properties of the matrices involved are derived with a view to application of numerical methods of solution. The Jacobi iterative method as applied to the current-balance eigenvalue problem is discussed
NLTE steady-state response matrix method.
Faussurier, G.; More, R. M.
2000-05-01
A connection between atomic kinetics and non-equilibrium thermodynamics has been recently established by using a collisional-radiative model modified to include line absorption. The calculated net emission can be expressed as a non-local thermodynamic equilibrium (NLTE) symmetric response matrix. In the paper, this connection is extended to both cases of the average-atom model and the Busquet's model (RAdiative-Dependent IOnization Model, RADIOM). The main properties of the response matrix still remain valid. The RADIOM source function found in the literature leads to a diagonal response matrix, stressing the absence of any frequency redistribution among the frequency groups at this order of calculation.
The finite element response matrix method
International Nuclear Information System (INIS)
Nakata, H.; Martin, W.R.
1983-02-01
A new technique is developed with an alternative formulation of the response matrix method implemented with the finite element scheme. Two types of response matrices are generated from the Galerkin solution to the weak form of the diffusion equation subject to an arbitrary current and source. The piecewise polynomials are defined in two levels, the first for the local (assembly) calculations and the second for the global (core) response matrix calculations. This finite element response matrix technique was tested in two 2-dimensional test problems, 2D-IAEA benchmark problem and Biblis benchmark problem, with satisfatory results. The computational time, whereas the current code is not extensively optimized, is of the same order of the well estabilished coarse mesh codes. Furthermore, the application of the finite element technique in an alternative formulation of response matrix method permits the method to easily incorporate additional capabilities such as treatment of spatially dependent cross-sections, arbitrary geometrical configurations, and high heterogeneous assemblies. (Author) [pt
The finite element response Matrix method
International Nuclear Information System (INIS)
Nakata, H.; Martin, W.R.
1983-01-01
A new method for global reactor core calculations is described. This method is based on a unique formulation of the response matrix method, implemented with a higher order finite element method. The unique aspects of this approach are twofold. First, there are two levels to the overall calculational scheme: the local or assembly level and the global or core level. Second, the response matrix scheme, which is formulated at both levels, consists of two separate response matrices rather than one response matrix as is generally the case. These separate response matrices are seen to be quite beneficial for the criticality eigenvalue calculation, because they are independent of k /SUB eff/. The response matrices are generated from a Galerkin finite element solution to the weak form of the diffusion equation, subject to an arbitrary incoming current and an arbitrary distributed source. Calculational results are reported for two test problems, the two-dimensional International Atomic Energy Agency benchmark problem and a two-dimensional pressurized water reactor test problem (Biblis reactor), and they compare well with standard coarse mesh methods with respect to accuracy and efficiency. Moreover, the accuracy (and capability) is comparable to fine mesh for a fraction of the computational cost. Extension of the method to treat heterogeneous assemblies and spatial depletion effects is discussed
Zhang, Xing; Carter, Emily A.
2018-01-01
We revisit the static response function-based Kohn-Sham (KS) inversion procedure for determining the KS effective potential that corresponds to a given target electron density within finite atomic orbital basis sets. Instead of expanding the potential in an auxiliary basis set, we directly update the potential in its matrix representation. Through numerical examples, we show that the reconstructed density rapidly converges to the target density. Preliminary results are presented to illustrate the possibility of obtaining a local potential in real space from the optimized potential in its matrix representation. We have further applied this matrix-based KS inversion approach to density functional embedding theory. A proof-of-concept study of a solvated proton transfer reaction demonstrates the method's promise.
Nodal coupling by response matrix principles
International Nuclear Information System (INIS)
Ancona, A.; Becker, M.; Beg, M.D.; Harris, D.R.; Menezes, A.D.; VerPlanck, D.M.; Pilat, E.
1977-01-01
The response matrix approach has been used in viewing a reactor node in isolation and in characterizing the node by reflection and trans-emission factors. These are then used to generate invariant imbedding parameters, which in turn are used in a nodal reactor simulator code to compute core power distributions in two and three dimensions. Various nodal techniques are analyzed and converted into a single invariant imbedding formalism
Nonlinear response matrix methods for radiative transfer
International Nuclear Information System (INIS)
Miller, W.F. Jr.; Lewis, E.E.
1987-01-01
A nonlinear response matrix formalism is presented for the solution of time-dependent radiative transfer problems. The essential feature of the method is that within each computational cell the temperature is calculated in response to the incoming photons from all frequency groups. Thus the updating of the temperature distribution is placed within the iterative solution of the spaceangle transport problem, instead of being placed outside of it. The method is formulated for both grey and multifrequency problems and applied in slab geometry. The method is compared to the more conventional source iteration technique. 7 refs., 1 fig., 4 tabs
Matrix Metalloproteinase Responsive Delivery of Myostatin Inhibitors.
Braun, Alexandra C; Gutmann, Marcus; Ebert, Regina; Jakob, Franz; Gieseler, Henning; Lühmann, Tessa; Meinel, Lorenz
2017-01-01
The inhibition of myostatin - a member of the transforming growth factor (TGF-β) family - drives regeneration of functional skeletal muscle tissue. We developed a bioresponsive drug delivery system (DDS) linking release of a myostatin inhibitor (MI) to inflammatory flares of myositis to provide self-regulated MI concentration gradients within tissues of need. A protease cleavable linker (PCL) - responding to MMP upregulation - is attached to the MI and site-specifically immobilized on microparticle surfaces. The PCL disintegrated in a matrix metalloproteinase (MMP) 1, 8, and particularly MMP-9 concentration dependent manner, with MMP-9 being an effective surrogate biomarker correlating with the activity of myositis. The bioactivity of particle-surface bound as well as released MI was confirmed by luciferase suppression in stably transfected HEK293 cells responding to myostatin induced SMAD phosphorylation. We developed a MMP-responsive DDS for MI delivery responding to inflammatory flare of a diseased muscle matching the kinetics of MMP-9 upregulation, with MMP-9 kinetics matching (patho-) physiological myostatin levels. ᅟ: Graphical Abstract Schematic illustration of the matrix metalloproteinase responsive delivery system responding to inflammatory flares of muscle disease. The protease cleavable linker readily disintegrates upon entry into the diseased tissue, therby releasing the mystatin inhibitor.
Orbit covariance propagation via quadratic-order state transition matrix in curvilinear coordinates
Hernando-Ayuso, Javier; Bombardelli, Claudio
2017-09-01
In this paper, an analytical second-order state transition matrix (STM) for relative motion in curvilinear coordinates is presented and applied to the problem of orbit uncertainty propagation in nearly circular orbits (eccentricity smaller than 0.1). The matrix is obtained by linearization around a second-order analytical approximation of the relative motion recently proposed by one of the authors and can be seen as a second-order extension of the curvilinear Clohessy-Wiltshire (C-W) solution. The accuracy of the uncertainty propagation is assessed by comparison with numerical results based on Monte Carlo propagation of a high-fidelity model including geopotential and third-body perturbations. Results show that the proposed STM can greatly improve the accuracy of the predicted relative state: the average error is found to be at least one order of magnitude smaller compared to the curvilinear C-W solution. In addition, the effect of environmental perturbations on the uncertainty propagation is shown to be negligible up to several revolutions in the geostationary region and for a few revolutions in low Earth orbit in the worst case.
Matrix isolation FT-IR spectroscopy and molecular orbital study of sarcosine methyl ester
Gómez-Zavaglia, Andrea; Fausto, R.
2004-01-01
N-methylglycine methyl ester (sarcosine-Me) has been studied by matrix isolation FT-IR spectroscopy and molecular orbital calculations undertaken at the DFT/B3LYP and MP2 levels of theory with the 6-311++G(d,p) and 6-31++G(d,p) basis set, respectively. Twelve different conformers were located in the potential energy surface of the studied compound, with the ASC conformer being the ground conformational state. This form is analogous to the dimethylglycine methyl ester most stable conformer and...
Construction of the Fock Matrix on a Grid-Based Molecular Orbital Basis Using GPGPUs.
Losilla, Sergio A; Watson, Mark A; Aspuru-Guzik, Alán; Sundholm, Dage
2015-05-12
We present a GPGPU implementation of the construction of the Fock matrix in the molecular orbital basis using the fully numerical, grid-based bubbles representation. For a test set of molecules containing up to 90 electrons, the total Hartree-Fock energies obtained from reference GTO-based calculations are reproduced within 10(-4) Eh to 10(-8) Eh for most of the molecules studied. Despite the very large number of arithmetic operations involved, the high performance obtained made the calculations possible on a single Nvidia Tesla K40 GPGPU card.
Directory of Open Access Journals (Sweden)
G. Franchetti
2008-09-01
Full Text Available In this paper we present a method for measuring the nonlinear errors in a circular accelerator by taking advantage of the feed-down effect of high order multipoles when the closed orbit is globally deformed. We devise a nonlinear tune response matrix in which the response to a closed orbit deformation is obtained in terms of change of machine tune and correlated with the strength of the local multipoles. A numerical example and a proof of principle experiment to validate the theoretical methods are presented and discussed.
Xu, Guochang
2008-01-01
This is the first book of the satellite era which describes orbit theory with analytical solutions of the second order with respect to all possible disturbances. Based on such theory, the algorithms of orbits determination are completely revolutionized.
Fundamentals of the orbit and response for TianQin
Hu, Xin-Chun; Li, Xiao-Hong; Wang, Yan; Feng, Wen-Fan; Zhou, Ming-Yue; Hu, Yi-Ming; Hu, Shou-Cun; Mei, Jian-Wei; Shao, Cheng-Gang
2018-05-01
TianQin is a space-based laser interferometric gravitational wave detector aimed at detecting gravitational waves at low frequencies (0.1 mHz–1 Hz). It is formed by three identical drag-free spacecrafts in an equilateral triangular constellation orbiting around the Earth. The distance between each pair of spacecrafts is approximately 1.7 × 105 ~km . The spacecrafts are interconnected by infrared laser beams forming up to three Michelson-type interferometers. The detailed mission design and the study of science objectives for the TianQin project depend crucially on the orbit and the response of the detector. In this paper, we provide the analytic expressions for the coordinates of the orbit for each spacecraft in the heliocentric-ecliptic coordinate system to the leading orders. This enables a sufficiently accurate study of science objectives and data analysis, and serves as a first step to further orbit design and optimization. We calculate the response of a single Michelson detector to plane gravitational waves in arbitrary waveform which is valid in the full range of the sensitive frequencies. It is then used to generate the more realistic sensitivity curve of TianQin. We apply this model on a reference white-dwarf binary as a proof of principle.
Orbital functionals in density-matrix- and current-density-functional theory
Energy Technology Data Exchange (ETDEWEB)
Helbig, N
2006-05-15
Density-Functional Theory (DFT), although widely used and very successful in the calculation of several observables, fails to correctly describe strongly correlated materials. In the first part of this work we, therefore, introduce reduced-densitymatrix- functional theory (RDMFT) which is one possible way to treat electron correlation beyond DFT. Within this theory the one-body reduced density matrix (1- RDM) is used as the basic variable. Our main interest is the calculation of the fundamental gap which proves very problematic within DFT. In order to calculate the fundamental gap we generalize RDMFT to fractional particle numbers M by describing the system as an ensemble of an N and an N+1 particle system (with N{<=}M{<=}N+1). For each fixed particle number, M, the total energy is minimized with respect to the natural orbitals and their occupation numbers. This leads to the total energy as a function of M. The derivative of this function with respect to the particle number has a discontinuity at integer particle number which is identical to the gap. In addition, we investigate the necessary and sufficient conditions for the 1- RDM of a system with fractional particle number to be N-representable. Numerical results are presented for alkali atoms, small molecules, and periodic systems. Another problem within DFT is the description of non-relativistic many-electron systems in the presence of magnetic fields. It requires the paramagnetic current density and the spin magnetization to be used as basic variables besides the electron density. However, electron-gas-based functionals of current-spin-density-functional Theory (CSDFT) exhibit derivative discontinuities as a function of the magnetic field whenever a new Landau level is occupied, which makes them difficult to use in practice. Since the appearance of Landau levels is, intrinsically, an orbital effect it is appealing to use orbital-dependent functionals. We have developed a CSDFT version of the optimized
Yourshaw, Matthew Stephen
2017-01-01
Orbital is a virtual reality gaming experience designed to explore the use of traditional narrative structure to enhance immersion in virtual reality. The story structure of Orbital was developed based on the developmental steps of 'The Hero's Journey,' a narrative pattern identified by Joseph Campbell. Using this standard narrative pattern, Orbital is capable of immersing the player quickly and completely for the entirety of play time. MFA
Response Matrix Method Development Program at Savannah River Laboratory
International Nuclear Information System (INIS)
Sicilian, J.M.
1976-01-01
The Response Matrix Method Development Program at Savannah River Laboratory (SRL) has concentrated on the development of an effective system of computer codes for the analysis of Savannah River Plant (SRP) reactors. The most significant contribution of this program to date has been the verification of the accuracy of diffusion theory codes as used for routine analysis of SRP reactor operation. This paper documents the two steps carried out in achieving this verification: confirmation of the accuracy of the response matrix technique through comparison with experiment and Monte Carlo calculations; and establishment of agreement between diffusion theory and response matrix codes in situations which realistically approximate actual operating conditions
Convergence Improvement of Response Matrix Method with Large Discontinuity Factors
International Nuclear Information System (INIS)
Yamamoto, Akio
2003-01-01
In the response matrix method, a numerical divergence problem has been reported when extremely small or large discontinuity factors are utilized in the calculations. In this paper, an alternative response matrix formulation to solve the divergence problem is discussed, and properties of iteration matrixes are investigated through eigenvalue analyses. In the conventional response matrix formulation, partial currents between adjacent nodes are assumed to be discontinuous, and outgoing partial currents are converted into incoming partial currents by the discontinuity factor matrix. Namely, the partial currents of the homogeneous system (i.e., homogeneous partial currents) are treated in the conventional response matrix formulation. In this approach, the spectral radius of an iteration matrix for the partial currents may exceed unity when an extremely small or large discontinuity factor is used. Contrary to this, an alternative response matrix formulation using heterogeneous partial currents is discussed in this paper. In the latter approach, partial currents are assumed to be continuous between adjacent nodes, and discontinuity factors are directly considered in the coefficients of a response matrix. From the eigenvalue analysis of the iteration matrix for the one-group, one-dimensional problem, the spectral radius for the heterogeneous partial current formulation does not exceed unity even if an extremely small or large discontinuity factor is used in the calculation; numerical stability of the alternative formulation is superior to the conventional one. The numerical stability of the heterogeneous partial current formulation is also confirmed by the two-dimensional light water reactor core analysis. Since the heterogeneous partial current formulation does not require any approximation, the converged solution exactly reproduces the reference solution when the discontinuity factors are directly derived from the reference calculation
Matrix isolation FT-IR spectroscopy and molecular orbital study of sarcosine methyl ester
Gómez-Zavaglia, A.; Fausto, R.
2004-02-01
N-methylglycine methyl ester (sarcosine-Me) has been studied by matrix isolation FT-IR spectroscopy and molecular orbital calculations undertaken at the DFT/B3LYP and MP2 levels of theory with the 6-311++G(d,p) and 6-31++G(d,p) basis set, respectively. Twelve different conformers were located in the potential energy surface of the studied compound, with the ASC conformer being the ground conformational state. This form is analogous to the dimethylglycine methyl ester most stable conformer and is characterized by a NH⋯O intramolecular hydrogen bond; in this form, the ester group assumes the cis configuration and the OC-C-N and Lp-N-C-C (where Lp is the nitrogen lone electron pair) dihedral angles are ca. -17.8 and 171.3°, respectively. The second most stable conformer ( GSC) differs from the ASC conformer essentially in the conformation assumed by the methylamino group, which in this case is gauche ( Lp-N-C-C dihedral angle equal to 79.4°). On the other hand, the third most stable conformer ( AAC) differs from the most stable form in the conformation of the OC-C-N axis (151.4°). These three forms were predicted to differ in energy by less than ca. 5 kJ mol -1 and represent ≈95% of the total conformational population at room temperature. FT-IR spectra were obtained for sarcosine-Me isolated in argon matrices (T=9 K) revealing the presence in the matrices of the three lowest energy conformers predicted by the calculations. The matrices were prepared by deposition of the vapour of the compound using two different nozzle temperatures, 25 and 60 °C. The relative populations of the three conformers trapped in the matrices were found to be consistent with occurrence of conformational cooling during matrix deposition and with a stabilization of the most polar GSC and AAC conformers in the matrices compared to the gas phase. Indeed, like it was previously observed for the methyl ester of dimethylglycine [Phys. Chem. Chem. Phys. 5 (2003) 52] the different
Litofsky, Joshua; Viswanathan, Rama
2015-01-01
Matrix diagonalization, the key technique at the heart of modern computational chemistry for the numerical solution of the Schrödinger equation, can be easily introduced in the physical chemistry curriculum in a pedagogical context using simple Hückel molecular orbital theory for p bonding in molecules. We present details and results of…
Matrix of response functions for xenon gamma-ray detector
International Nuclear Information System (INIS)
Shustov, A.E.; Vlasik, K.F.; Grachev, V.M.; Dmitrenko, V.V.; Novikov, A.S.; P'ya, S.N.; Ulin, S.E.; Uteshev, Z.M.; Chernysheva, I.V.
2014-01-01
An approach of creation of response matrix using simulation GEANT4 gamma-ray Monte-Carlo method has been described for gamma-ray spectrometer based on high pressure xenon impulse ionization chamber with a shielding grid [ru
A nodal method based on matrix-response method
International Nuclear Information System (INIS)
Rocamora Junior, F.D.; Menezes, A.
1982-01-01
A nodal method based in the matrix-response method, is presented, and its application to spatial gradient problems, such as those that exist in fast reactors, near the core - blanket interface, is investigated. (E.G.) [pt
International Nuclear Information System (INIS)
Yim, M.B.; DiGregorio, S.; Wood, D.E.
1977-01-01
Pentafluoropyridine,2,3,4,6-tetrafluoropyridine, 2,6-difluoropyridine, and 2-fluoropyridine anion radicals were produced by x irradiation of an adamantane matrix which was doubly doped with the aromatic precursors and Me 3 NBH 3 and their EPR spectra obtained. The large fluorine hyperfine splitting constants (hfsc) of penta- and 2,3,4,6-tetrafluoropyridine anions and the small fluorine hfsc's of 2,6-di- and 2-fluoropyridine anions suggest that the former two are sigma radicals while the latter two are π radicals. The sigma*-π* orbital crossover phenomenon observed in these fluorinated pyridine anions is explained in terms of the combined effects of stabilization of sigma* orbitals and destabilization of π* orbitals. The EPR results show that nitrogen has a negligible contribution to the unpaired electron sigma* orbitals. INDO calculations were performed for the various states and the results compared with experiment
ARE TIDAL EFFECTS RESPONSIBLE FOR EXOPLANETARY SPIN–ORBIT ALIGNMENT?
Energy Technology Data Exchange (ETDEWEB)
Li, Gongjie [Harvard-Smithsonian Center for Astrophysics, The Institute for Theory and Computation, 60 Garden Street, Cambridge, MA 02138 (United States); Winn, Joshua N., E-mail: gli@cfa.harvard.edu [Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)
2016-02-10
The obliquities of planet-hosting stars are clues about the formation of planetary systems. Previous observations led to the hypothesis that for close-in giant planets, spin–orbit alignment is enforced by tidal interactions. Here, we examine two problems with this hypothesis. First, Mazeh and coworkers recently used a new technique—based on the amplitude of starspot-induced photometric variability—to conclude that spin–orbit alignment is common even for relatively long-period planets, which would not be expected if tides were responsible. We re-examine the data and find a statistically significant correlation between photometric variability and planetary orbital period that is qualitatively consistent with tidal interactions. However it is still difficult to explain quantitatively, as it would require tides to be effective for periods as long as tens of days. Second, Rogers and Lin argued against a particular theory for tidal re-alignment by showing that initially retrograde systems would fail to be re-aligned, in contradiction with the observed prevalence of prograde systems. We investigate a simple model that overcomes this problem by taking into account the dissipation of inertial waves and the equilibrium tide, as well as magnetic braking. We identify a region of parameter space where re-alignment can be achieved, but it only works for close-in giant planets, and requires some fine tuning. Thus, while we find both problems to be more nuanced than they first appeared, the tidal model still has serious shortcomings.
Finite orbit energetic particle linear response to toroidal Alfven eigenmodes
International Nuclear Information System (INIS)
Berk, H.L.; Ye, Huanchun; Breizman, B.N.
1991-07-01
The linear response of energetic particles to the TAE modes is calculated taking into account their finite orbit excursion from the flux surfaces. The general expression reproduces the previously derived theory for small banana width: when the banana width triangle b is much larger than the mode thickness triangle m , we obtain a new compact expression for the linear power transfer. When triangle m /triangle b much-lt 1, the banana orbit effect reduces the power transfer by a factor of triangle m /triangle b from that predicted by the narrow orbit theory. A comparison is made of the contribution to the TAE growth rate of energetic particles with a slowing-down distribution arising from an isotropic source, and a balance-injected beam source when the source speed is close to the Alfven speed. For the same stored energy density, the contribution from the principal resonances (|υ parallel | = υ A is substantially enhanced in the beam case compared to the isotropic case, while the contribution at the higher sidebands (|υ parallel |) = υ A /(2 ell - 1) with ell ≥ 2) is substantially reduced. 10 refs
Energy Technology Data Exchange (ETDEWEB)
Roemelt, Michael, E-mail: michael.roemelt@theochem.rub.de [Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, D-44780 Bochum, Germany and Max-Planck Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr (Germany)
2015-07-28
Spin Orbit Coupling (SOC) is introduced to molecular ab initio density matrix renormalization group (DMRG) calculations. In the presented scheme, one first approximates the electronic ground state and a number of excited states of the Born-Oppenheimer (BO) Hamiltonian with the aid of the DMRG algorithm. Owing to the spin-adaptation of the algorithm, the total spin S is a good quantum number for these states. After the non-relativistic DMRG calculation is finished, all magnetic sublevels of the calculated states are constructed explicitly, and the SOC operator is expanded in the resulting basis. To this end, spin orbit coupled energies and wavefunctions are obtained as eigenvalues and eigenfunctions of the full Hamiltonian matrix which is composed of the SOC operator matrix and the BO Hamiltonian matrix. This treatment corresponds to a quasi-degenerate perturbation theory approach and can be regarded as the molecular equivalent to atomic Russell-Saunders coupling. For the evaluation of SOC matrix elements, the full Breit-Pauli SOC Hamiltonian is approximated by the widely used spin-orbit mean field operator. This operator allows for an efficient use of the second quantized triplet replacement operators that are readily generated during the non-relativistic DMRG algorithm, together with the Wigner-Eckart theorem. With a set of spin-orbit coupled wavefunctions at hand, the molecular g-tensors are calculated following the scheme proposed by Gerloch and McMeeking. It interprets the effective molecular g-values as the slope of the energy difference between the lowest Kramers pair with respect to the strength of the applied magnetic field. Test calculations on a chemically relevant Mo complex demonstrate the capabilities of the presented method.
Transverse impedance measurement using response matrix fit method at APS
International Nuclear Information System (INIS)
Sajaev, V.
2007-01-01
of an accelerator. The orbit bump method was done at BINP, APS, and ESRF. All these methods have one common feature: they employ the fact that the beam sees the impedance as an additional defocusing quadrupole whose strength depends on the beam current. At APS we use an orbit response matrix fit to determine the distribution of focusing errors around the machine, and then use these errors to calculate beta functions. Since the beam sees the impedance as a quadrupole whose strength depends on the beam current, the measurement of the beta functions with different currents could be used to determine the impedance distribution around the machine. This approach was first used at APS and reported in.
Finite orbit energetic particle linear response to toroidal Alfven eigenmodes
International Nuclear Information System (INIS)
Berk, H.L.; Ye Huanchun; Breizman, B.N.
1992-01-01
The linear response of energetic particles of the TAE modes is calculated taking into account their finite orbit excursion from the flux surfaces. The general expression reproduces the previously derived theory for small banana width; when the banana width Δ b is much larger than the mode thickness Δ m , we obtain a new compact expression for the linear power transfer. When Δ m /Δ b m /Δ b from that predicted by the narrow orbit theory. A comparison is made of the contribution to the TAE growth rate of energetic particles with a slowing-down distribution arising from an isotropic source, and a balanced-injected beam source when the source speed is close to the Alfven speed. For the same stored energy density, the contribution from the principal resonances (vertical strokev parallel vertical stroke=v A ) is substantially enhanced in the beam case compared to the isotropic case, while the contribution at the higher sidebands (vertical strokev parallel vertical stroke=v A /(2l-1) with l≥2) is substantially reduced. (orig.)
A Detailed Derivation of Gaussian Orbital-Based Matrix Elements in Electron Structure Calculations
Petersson, T.; Hellsing, B.
2010-01-01
A detailed derivation of analytic solutions is presented for overlap, kinetic, nuclear attraction and electron repulsion integrals involving Cartesian Gaussian-type orbitals. It is demonstrated how s-type orbitals can be used to evaluate integrals with higher angular momentum via the properties of Hermite polynomials and differentiation with…
A nodal method based on the response-matrix method
International Nuclear Information System (INIS)
Cunha Menezes Filho, A. da; Rocamora Junior, F.D.
1983-02-01
A nodal approach based on the Response-Matrix method is presented with the purpose of investigating the possibility of mixing two different allocations in the same problem. It is found that the use of allocation of albedo combined with allocation of direct reflection produces good results for homogeneous fast reactor configurations. (Author) [pt
Van Meer, R.; Gritsenko, O. V.; Baerends, E. J.
2017-01-01
Straightforward interpretation of excitations is possible if they can be described as simple single orbital-to-orbital (or double, etc.) transitions. In linear response time-dependent density functional theory (LR-TDDFT), the (ground state) Kohn-Sham orbitals prove to be such an orbital basis. In
Circular revisit orbits design for responsive mission over a single target
Li, Taibo; Xiang, Junhua; Wang, Zhaokui; Zhang, Yulin
2016-10-01
The responsive orbits play a key role in addressing the mission of Operationally Responsive Space (ORS) because of their capabilities. These capabilities are usually focused on supporting specific targets as opposed to providing global coverage. One subtype of responsive orbits is repeat coverage orbit which is nearly circular in most remote sensing applications. This paper deals with a special kind of repeating ground track orbit, referred to as circular revisit orbit. Different from traditional repeat coverage orbits, a satellite on circular revisit orbit can visit a target site at both the ascending and descending stages in one revisit cycle. This typology of trajectory allows a halving of the traditional revisit time and does a favor to get useful information for responsive applications. However the previous reported numerical methods in some references often cost lots of computation or fail to obtain such orbits. To overcome this difficulty, an analytical method to determine the existence conditions of the solutions to revisit orbits is presented in this paper. To this end, the mathematical model of circular revisit orbit is established under the central gravity model and the J2 perturbation. A constraint function of the circular revisit orbit is introduced, and the monotonicity of that function has been studied. The existent conditions and the number of such orbits are naturally worked out. Taking the launch cost into consideration, optimal design model of circular revisit orbit is established to achieve a best orbit which visits a target twice a day in the morning and in the afternoon respectively for several days. The result shows that it is effective to apply circular revisit orbits in responsive application such as reconnoiter of natural disaster.
Sayfutyarova, Elvira R.; Chan, Garnet Kin-Lic
2018-05-01
We present a state interaction spin-orbit coupling method to calculate electron paramagnetic resonance g-tensors from density matrix renormalization group wavefunctions. We apply the technique to compute g-tensors for the TiF3 and CuCl42 - complexes, a [2Fe-2S] model of the active center of ferredoxins, and a Mn4CaO5 model of the S2 state of the oxygen evolving complex. These calculations raise the prospects of determining g-tensors in multireference calculations with a large number of open shells.
Gómez-Zavaglia, Andrea; Fausto, R.
2003-01-01
Sarcosine (N-methylglycine) has been studied by matrix-isolation FT-IR spectroscopy and molecular orbital calculations undertaken at the DFT/B3LYP and MP2 levels of theory with the 6-311++G(d, p) and 6-31++G(d, p) basis set, respectively. Eleven different conformers were located in the potential energy surface (PES) of sarcosine, with the ASC conformer being the ground conformational state. This form is analogous to the glycine most stable conformer and is characterized by a NH...O= intramole...
A discrete ordinate response matrix method for massively parallel computers
International Nuclear Information System (INIS)
Hanebutte, U.R.; Lewis, E.E.
1991-01-01
A discrete ordinate response matrix method is formulated for the solution of neutron transport problems on massively parallel computers. The response matrix formulation eliminates iteration on the scattering source. The nodal matrices which result from the diamond-differenced equations are utilized in a factored form which minimizes memory requirements and significantly reduces the required number of algorithm utilizes massive parallelism by assigning each spatial node to a processor. The algorithm is accelerated effectively by a synthetic method in which the low-order diffusion equations are also solved by massively parallel red/black iterations. The method has been implemented on a 16k Connection Machine-2, and S 8 and S 16 solutions have been obtained for fixed-source benchmark problems in X--Y geometry
Empirically Determined Response Matrices for On-Line Orbit and Energy Correction at Jefferson Lab
International Nuclear Information System (INIS)
Leigh Harwood; Alicia Hofler; Michele Joyce; Valeri Lebedev; David Bryan
2001-01-01
Jefferson Lab uses feedback loops (less than 1 hertz update rate) to correct drifts in CEBAF's electron beam orbit and energy. Previous incarnations of these loops used response matrices that were computed by a numerical model of the machine. Jefferson Lab is transitioning this feedback system to use empirically determined response matrices whereby the software introduces small orbit or energy deviations using the loop's actuators and measures the system response with the loop's sensors. This method is in routine use for orbit correction. This paper will describe the orbit correction system and future plans to extend this method to energy correction
Extracellular matrix organization modulates fibroblast growth and growth factor responsiveness.
Nakagawa, S; Pawelek, P; Grinnell, F
1989-06-01
To learn more about the relationship between extracellular matrix organization, cell shape, and cell growth control, we studied DNA synthesis by fibroblasts in collagen gels that were either attached to culture dishes or floating in culture medium during gel contraction. After 4 days of contraction, the collagen density (initially 1.5 mg/ml) reached 22 mg/ml in attached gels and 55 mg/ml in floating gels. After contraction, attached collagen gels were well organized; collagen fibrils were aligned in the plane of cell spreading; and fibroblasts had an elongated, bipolar morphology. Floating collagen gels, however, were unorganized; collagen fibrils were arranged randomly; and fibroblasts had a stellate morphology. DNA synthesis by fibroblasts in contracted collagen gels was suppressed if the gels were floating in medium but not if the gels were attached, and inhibition was independent of the extent of gel contraction. Therefore, growth of fibroblasts in contracted collagen gels could be regulated by differences in extracellular matrix organization and cell shape independently of extracellular matrix density. We also compared the responses of fibroblasts in contracted collagen gels and monolayer culture to peptide growth factors including fibroblast growth factor, platelet-derived growth factor, transforming growth factor-beta, and interleukin 1. Cells in floating collagen gels were generally unresponsive to any of the growth factors. Cells in attached collagen gels and monolayer culture were affected similarly by fibroblast growth factor but not by the others. Our results indicate that extracellular matrix organization influenced not only cell growth, but also fibroblast responsiveness to peptide growth factors.
Massively parallel performance of neutron transport response matrix algorithms
International Nuclear Information System (INIS)
Hanebutte, U.R.; Lewis, E.E.
1993-01-01
Massively parallel red/black response matrix algorithms for the solution of within-group neutron transport problems are implemented on the Connection Machines-2, 200 and 5. The response matrices are dericed from the diamond-differences and linear-linear nodal discrete ordinate and variational nodal P 3 approximations. The unaccelerated performance of the iterative procedure is examined relative to the maximum rated performances of the machines. The effects of processor partitions size, of virtual processor ratio and of problems size are examined in detail. For the red/black algorithm, the ratio of inter-node communication to computing times is found to be quite small, normally of the order of ten percent or less. Performance increases with problems size and with virtual processor ratio, within the memeory per physical processor limitation. Algorithm adaptation to courser grain machines is straight-forward, with total computing time being virtually inversely proportional to the number of physical processors. (orig.)
International Nuclear Information System (INIS)
Smeyers, Y.G.; Delgado-Barrio, G.
1976-01-01
The half-projected Hartree--Fock function for singlet states (HPHF) is analyzed in terms of natural electronic configurations. For this purpose the HPHF spinless density matrix and its natural orbitals are first deduced. It is found that the HPHF function does not contain any contribution from odd-times excited configurations. It is seen in addition, in the case of the singlet ground states, this function is approximately equivalent to two closed-shell configurations, although the nature of the excited one depends on the nuclear geometry. An example is given in the case of the LiH ground state. Finally, the application of this model for studying systems of more than two atoms is criticized
Spin alignment and density matrix measurement in 28Si + 12C orbiting reaction
International Nuclear Information System (INIS)
Ray, A.; Shapira, D.; Halbert, M.L.; Gomez del Campo, J.; Kim, H.J.; Sullivan, J.P.; Shivakumar, B.; Mitchell, J.
1990-01-01
Gamma-ray angular correlations have been measured for the strongly damped reactions 12 C( 28 Si, 12 C) 28 Si between θ cm = (120 degree - 160 degree) for E cm = 43.5 and 48 MeV. We find that the density matrices for the 12 C(2 1 + ) and 28 Si states are almost diagonal with respect to the direction of motion of the outgoing particle. The measured density matrices and spin alignments are consistent with the picture of formation of a long-lived dinuclear complex undergoing orbiting, bending and wriggling motions, but not with those obtained from statistical compound nucleus or sticking model calculations. 17 refs., 2 figs., 1 tab
Stoykov, S.; Atanassov, E.; Margenov, S.
2016-10-01
Many of the scientific applications involve sparse or dense matrix operations, such as solving linear systems, matrix-matrix products, eigensolvers, etc. In what concerns structural nonlinear dynamics, the computations of periodic responses and the determination of stability of the solution are of primary interest. Shooting method iswidely used for obtaining periodic responses of nonlinear systems. The method involves simultaneously operations with sparse and dense matrices. One of the computationally expensive operations in the method is multiplication of sparse by dense matrices. In the current work, a new algorithm for sparse matrix by dense matrix products is presented. The algorithm takes into account the structure of the sparse matrix, which is obtained by space discretization of the nonlinear Mindlin's plate equation of motion by the finite element method. The algorithm is developed to use the vector engine of Intel Xeon Phi coprocessors. It is compared with the standard sparse matrix by dense matrix algorithm and the one developed by Intel MKL and it is shown that by considering the properties of the sparse matrix better algorithms can be developed.
International Nuclear Information System (INIS)
Holas, A.; Cinal, M.
2005-01-01
Three approximate exchange potentials of high accuracy v x Y (r), Y=A,B,C, for the density-functional theory applications are obtained by replacing the matrix elements of the exact potential between the Kohn-Sham (KS) orbitals with such elements of the Fock exchange operator (within the virtual-occupied subset only) in three representations found for any local potential. A common identity is the base of these representations. The potential v x C happens to be the same as that derived by Harbola and Sahni, and v x A as that derived by Gritsenko and Baerends, and Della Sala and Goerling. The potentials obtained can be expressed in terms of occupied KS orbitals only. At large r, their asymptotic form -1/r is the same as that of the exact potential. The high quality of these three approximations is demonstrated by direct comparison with the exact potential and using various consistency tests. A common root established for the three approximations could be helpful in finding new and better approximations via modification of identities employed in the present investigation
Solving eigenvalue response matrix equations with nonlinear techniques
International Nuclear Information System (INIS)
Roberts, Jeremy A.; Forget, Benoit
2014-01-01
Highlights: • High performance solvers were applied within ERMM for the first time. • Accelerated fixed-point methods were developed that reduce computational times by 2–3. • A nonlinear, Newton-based ERMM led to similar improvement and more robustness. • A 3-D, SN-based ERMM shows how ERMM can apply fine-mesh methods to full-core analysis. - Abstract: This paper presents new algorithms for use in the eigenvalue response matrix method (ERMM) for reactor eigenvalue problems. ERMM spatially decomposes a domain into independent nodes linked via boundary conditions approximated as truncated orthogonal expansions, the coefficients of which are response functions. In its simplest form, ERMM consists of a two-level eigenproblem: an outer Picard iteration updates the k-eigenvalue via balance, while the inner λ-eigenproblem imposes neutron balance between nodes. Efficient methods are developed for solving the inner λ-eigenvalue problem within the outer Picard iteration. Based on results from several diffusion and transport benchmark models, it was found that the Krylov–Schur method applied to the λ-eigenvalue problem reduces Picard solver times (excluding response generation) by a factor of 2–5. Furthermore, alternative methods, including Picard acceleration schemes, Steffensen’s method, and Newton’s method, are developed in this paper. These approaches often yield faster k-convergence and a need for fewer k-dependent response function evaluations, which is important because response generation is often the primary cost for problems using responses computed online (i.e., not from a precomputed database). Accelerated Picard iteration was found to reduce total computational times by 2–3 compared to the unaccelerated case for problems dominated by response generation. In addition, Newton’s method was found to provide nearly the same performance with improved robustness
Production of matrix metalloproteinases in response to mycobacterial infection.
Quiding-Järbrink, M; Smith, D A; Bancroft, G J
2001-09-01
Matrix metalloproteinases (MMPs) constitute a large family of enzymes with specificity for the various proteins of the extracellular matrix which are implicated in tissue remodeling processes and chronic inflammatory conditions. To investigate the role of MMPs in immunity to mycobacterial infections, we incubated murine peritoneal macrophages with viable Mycobacterium bovis BCG or Mycobacterium tuberculosis H37Rv and assayed MMP activity in the supernatants by zymography. Resting macrophages secreted only small amounts of MMP-9 (gelatinase B), but secretion increased dramatically in a dose-dependent manner in response to either BCG or M. tuberculosis in vitro. Incubation with mycobacteria also induced increased MMP-2 (gelatinase A) activity. Neutralization of tumor necrosis alpha (TNF-alpha), and to a lesser extent interleukin 18 (IL-18), substantially reduced MMP production in response to mycobacteria. Exogenous addition of TNF-alpha or IL-18 induced macrophages to express MMPs, even in the absence of bacteria. The immunoregulatory cytokines gamma interferon (IFN-gamma), IL-4, and IL-10 all suppressed BCG-induced MMP production, but through different mechanisms. IFN-gamma treatment increased macrophage secretion of TNF-alpha but still reduced their MMP activity. Conversely, IL-4 and IL-10 seemed to act by reducing the amount of TNF-alpha available to the macrophages. Finally, infection of BALB/c or severe combined immunodeficiency (SCID) mice with either BCG or M. tuberculosis induced substantial increases in MMP-9 activity in infected tissues. In conclusion, we show that mycobacterial infection induces MMP-9 activity both in vitro and in vivo and that this is regulated by TNF-alpha, IL-18, and IFN-gamma. These findings indicate a possible contribution of MMPs to tissue remodeling processes that occur in mycobacterial infections.
International Nuclear Information System (INIS)
Pivovarchik, V.N.; Poplavskij, I.V.
1982-01-01
The asymptotic behaviour of the regular solution, the Yost function and the S-matrix of the Schrodinger equation is estimated by means of WKB quasiclassical method at a fixed physical value of energy (k>0) for lambda→infinity in the domain Re lambda→0 for central and spin-orbital interaction [ru
Bultinck, Patrick; Van Neck, Dimitri; Acke, Guillaume; Ayers, Paul W
2012-02-21
The Fukui function is considered as the diagonal element of the Fukui matrix in position space, where the Fukui matrix is the derivative of the one particle density matrix (1DM) with respect to the number of electrons. Diagonalization of the Fukui matrix, expressed in an orthogonal orbital basis, explains why regions in space with negative Fukui functions exist. Using a test set of molecules, electron correlation is found to have a remarkable effect on the eigenvalues of the Fukui matrix. The Fukui matrices at the independent electron model level are mathematically proven to always have an eigenvalue equal to exactly unity while the rest of the eigenvalues possibly differ from zero but sum to zero. The loss of idempotency of the 1DM at correlated levels of theory causes the loss of these properties. The influence of electron correlation is examined in detail and the frontier molecular orbital concept is extended to correlated levels of theory by defining it as the eigenvector of the Fukui matrix with the largest eigenvalue. The effect of degeneracy on the Fukui matrix is examined in detail, revealing that this is another way by which the unity eigenvalue and perfect pairing of eigenvalues can disappear.
Algorithms for orbit control on SPEAR
International Nuclear Information System (INIS)
Corbett, J.; Keeley, D.; Hettel, R.; Linscott, I.; Sebek, J.
1994-06-01
A global orbit feedback system has been installed on SPEAR to help stabilize the position of the photon beams. The orbit control algorithms depend on either harmonic reconstruction of the orbit or eigenvector decomposition. The orbit motion is corrected by dipole corrector kicks determined from the inverse corrector-to-bpm response matrix. This paper outlines features of these control algorithms as applied to SPEAR
Neutron response matrix for unfolding NE-213 measurements to 21 MeV
International Nuclear Information System (INIS)
Ingersoll, D.T.; Wehring, B.W.; Johnson, R.H.
1976-01-01
A neutron response matrix from measured neutron responses of NE-213 in the energy range of 0.2 to 22 MeV is presented. An interpolation scheme was used to construct an 81-column matrix from the data of Verbinski, Burrus, Love, Zobel, and Hill. As a test of the new response matrix, the Cf-252 neutron spectrum was measured and unfolded using the new response matrix and the FORIST unfolding code. The spectrum agrees well with previous measurements at lower energies, while providing new information above 8 MeV
Linear and nonlinear response matrix and its application to the SIS18 synchrotron
International Nuclear Information System (INIS)
Parfenova, Angelina
2008-01-01
This Thesis is dedicated to the numerical as well as the experimental study of beam dynamics in circular accelerators. The experimental part was undertaken in the SIS18 synchrotron. The detailed description of the experiments contained in this work can be considered as a starting point for future experiments and machine development. The work has the following structure. In Chapter 2 an overview of the GSI and FAIR accelerator facilities, and a general description of the SIS18 instrumentation related to the study of this work are given. The expected SIS18 performance in view of the upgrade program for FAIR project are outlined. The main beam dynamics issues connected with the purpose of this work are discussed. Chapter 3 is devoted to the study of linear beam dynamics in the SIS18. The resonance beam loss measurements were carried out with residual gas profile monitor in the SIS18 (Chapter 4). In the frame of this work a novel technique 'nonlinear tune response matrix method' to identify strengths, polarities and locations of nonlinear errors in circular accelerators is developed (Chapter 5). In the method the feed down effect of the nonlinear components at level of linear tune response to the closed-orbit change is explored. The closed-orbit change is introduced by varying correction steerers. The tune values are retrieved from the spectrum of coherent betatron oscillations excited by a fast kick. The theoretical background, the robustness of the method and numerical examples for the SIS18 using numerical library MICROMAP are presented. The technique to measure lattice nonlinearities was experimentally validated in the SIS18 where two normal as well as two skew sextupolar errors of the order of natural errors were reconstructed with a tolerant precision. It was shown how this technique can be applied to reconstruct sextupolar nonlinear errors in the complete machine. In Chapter 6 the main results and the conclusions of this work are outlined. (orig.)
Chen, Zhenhua; Chen, Xun; Wu, Wei
2013-04-01
In this series, the n-body reduced density matrix (n-RDM) approach for nonorthogonal orbitals and their applications to ab initio valence bond (VB) methods are presented. As the first paper of this series, Hamiltonian matrix elements between internally contracted VB wave functions are explicitly provided by means of nonorthogonal orbital based RDM approach. To this end, a more generalized Wick's theorem, called enhanced Wick's theorem, is presented both in arithmetical and in graphical forms, by which the deduction of expressions for the matrix elements between internally contracted VB wave functions is dramatically simplified, and the matrix elements are finally expressed in terms of tensor contractions of electronic integrals and n-RDMs of the reference VB self-consistent field wave function. A string-based algorithm is developed for the purpose of evaluating n-RDMs in an efficient way. Using the techniques presented in this paper, one is able to develop new methods and efficient algorithms for nonorthogonal orbital based many-electron theory much easier than by use of the first quantized formulism.
International Nuclear Information System (INIS)
Kollmar, Christian; Neese, Frank
2014-01-01
The role of the static Kohn-Sham (KS) response function describing the response of the electron density to a change of the local KS potential is discussed in both the theory of the optimized effective potential (OEP) and the so-called inverse Kohn-Sham problem involving the task to find the local KS potential for a given electron density. In a general discussion of the integral equation to be solved in both cases, it is argued that a unique solution of this equation can be found even in case of finite atomic orbital basis sets. It is shown how a matrix representation of the response function can be obtained if the exchange-correlation potential is expanded in terms of a Schmidt-orthogonalized basis comprising orbitals products of occupied and virtual orbitals. The viability of this approach in both OEP theory and the inverse KS problem is illustrated by numerical examples
Islamiyati, A.; Fatmawati; Chamidah, N.
2018-03-01
The correlation assumption of the longitudinal data with bi-response occurs on the measurement between the subjects of observation and the response. It causes the auto-correlation of error, and this can be overcome by using a covariance matrix. In this article, we estimate the covariance matrix based on the penalized spline regression model. Penalized spline involves knot points and smoothing parameters simultaneously in controlling the smoothness of the curve. Based on our simulation study, the estimated regression model of the weighted penalized spline with covariance matrix gives a smaller error value compared to the error of the model without covariance matrix.
Response matrix properties and convergence implications for an interface-current nodal formulation
International Nuclear Information System (INIS)
Yang, W.S.
1995-01-01
An analytic study was performed of the properties and the associated convergence implications of the response matrix equations derived via the widely used nodal expansion method. By using the DIF3D nodal formulation in hexagonal-z geometry as a concrete example, an analytic expression for the response matrix is first derived by using the hexagonal prism symmetry transformations. The spectral radius of the local response matrix is shown to be always 2 -norm of the response matrix is shown to be ∞ -norm is not always 2 - and l ∞ -norms of the response matrix are found to increase as the removal cross section decreases. On the other hand, for a given removal cross section, each of these matrix norms takes its minimum at a certain diffusion coefficient and increases as the diffusion coefficient deviates from this value. Based on these matrix norms, sufficient conditions for the convergence of the iteration schemes for solving the response matrix equations are discussed. The range of node-height-to-hexagon-pitch ratios that guarantees a positive solution is derived as a function of the diffusion coefficient and the removal cross section
Novel load responsive multilayer insulation with high in-atmosphere and on-orbit thermal performance
Dye, S.; Kopelove, A.; Mills, G. L.
2012-04-01
Aerospace cryogenic systems require lightweight, high performance thermal insulation to preserve cryopropellants both pre-launch and on-orbit. Current technologies have difficulty meeting all requirements, and advances in insulation would benefit cryogenic upper stage launch vehicles, LH2 fueled aircraft and ground vehicles, and provide capabilities for sub-cooled cryogens for space-borne instruments and orbital fuel depots. This paper reports the further development of load responsive multilayer insulation (LRMLI) that has a lightweight integrated vacuum shell and provides high thermal performance both in-air and on-orbit. LRMLI is being developed by Quest Product Development and Ball Aerospace under NASA contract, with prototypes designed, built, installed and successfully tested. A 3-layer LRMLI blanket (0.63 cm thick, 77 K cold, 295 K hot) had a measured heat leak of 6.6 W/m2 in vacuum and 40.6 W/m2 in air at one atmosphere. In-air LRMLI has an 18× advantage over Spray On Foam Insulation (SOFI) in heat leak per thickness and a 16× advantage over aerogel. On-orbit LRMLI has a 78× lower heat leak than SOFI per thickness and 6× lower heat leak than aerogel. The Phase II development of LRMLI is reported with a modular, flexible, thin vacuum shell and improved on-orbit performance. Structural and thermal analysis and testing results are presented. LRMLI mass and thermal performance is compared to SOFI, aerogel and MLI over SOFI.
The effect of the food matrix on In Vivo immune responses to purified peanut allergens
Wijk, F. van; Nierkens, S.; Hassing, I.; Feijen, M.; Koppelman, S.J.; Jong, G.A.H. de; Pieters, R.; Knippels, L.M.J.
2005-01-01
There is little knowledge about the factors that determine the allergenicity of food proteins. One aspect that remains to be elucidated is the effect of the food matrix on immune responses to food proteins. To study the intrinsic immunogenicity of allergens and the influence of the food matrix,
The effect of the food matrix on in vivo immune responses to purified peanut allergens.
Wijk, F. van; Nierkens, S.; Hassing, I.; Feijen, M.; Koppelman, S.J.; Jong, G.A. de; Pieters, R.; Knippels, L.M.
2005-01-01
There is little knowledge about the factors that determine the allergenicity of food proteins. One aspect that remains to be elucidated is the effect of the food matrix on immune responses to food proteins. To study the intrinsic immunogenicity of allergens and the influence of the food matrix,
Energy Technology Data Exchange (ETDEWEB)
Jackson, C S [Program in Atmospheric and Oceanic Sciences, Princeton University, NJ 08542, Princeton (United States); Institute for Geophysics, The John A. and Katherine G. Jackson School of Geosciences, The University of Texas at Austin, 4412 Spicewood Springs Rd., Bldg 600, TX 78759, Austin (United States); Broccoli, A J [NOAA/Geophysical Fluid Dynamics Laboratory, NJ 08542, Princeton (United States); Department of Environmental Sciences, Rutgers University, NJ 08903, New Brunswick (United States)
2003-12-01
Progress in understanding how terrestrial ice volume is linked to Earth's orbital configuration has been impeded by the cost of simulating climate system processes relevant to glaciation over orbital time scales (10{sup 3}-10{sup 5} years). A compromise is usually made to represent the climate system by models that are averaged over one or more spatial dimensions or by three-dimensional models that are limited to simulating particular ''snapshots'' in time. We take advantage of the short equilibration time ({proportional_to}10 years) of a climate model consisting of a three-dimensional atmosphere coupled to a simple slab ocean to derive the equilibrium climate response to accelerated variations in Earth's orbital configuration over the past 165,000 years. Prominent decreases in ice melt and increases in snowfall are simulated during three time intervals near 26, 73, and 117 thousand years ago (ka) when aphelion was in late spring and obliquity was low. There were also significant decreases in ice melt and increases in snowfall near 97 and 142 ka when eccentricity was relatively large, aphelion was in late spring, and obliquity was high or near its long term mean. These ''glaciation-friendly'' time intervals correspond to prominent and secondary phases of terrestrial ice growth seen within the marine {delta}{sup 18}O record. Both dynamical and thermal effects contribute to the increases in snowfall during these periods, through increases in storm activity and the fraction of precipitation falling as snow. The majority of the mid- to high latitude response to orbital forcing is organized by the properties of sea ice, through its influence on radiative feedbacks that nearly double the size of the orbital forcing as well as its influence on the seasonal evolution of the latitudinal temperature gradient. (orig.)
Effects of mistuning and matrix structure on the topology of frequency response curves
Afolabi, Dare
1989-01-01
The stability of a frequency response curve under mild perturbations of the system's matrix is investigated. Using recent developments in the theory of singularities of differentiable maps, it is shown that the stability of a response curve depends on the structure of the system's matrix. In particular, the frequency response curves of a cylic system are shown to be unstable. Consequently, slight parameter variations engendered by mistuning will induce a significant difference in the topology of the forced response curves, if the mistuning transformation crosses the bifurcation set.
International Nuclear Information System (INIS)
Meer, R. van; Gritsenko, O. V.; Baerends, E. J.
2014-01-01
Time dependent density matrix functional theory in its adiabatic linear response formulation delivers exact excitation energies ω α and oscillator strengths f α for two-electron systems if extended to the so-called phase including natural orbital (PINO) theory. The Löwdin-Shull expression for the energy of two-electron systems in terms of the natural orbitals and their phases affords in this case an exact phase-including natural orbital functional (PILS), which is non-primitive (contains other than just J and K integrals). In this paper, the extension of the PILS functional to N-electron systems is investigated. With the example of an elementary primitive NO functional (BBC1) it is shown that current density matrix functional theory ground state functionals, which were designed to produce decent approximations to the total energy, fail to deliver a qualitatively correct structure of the (inverse) response function, due to essential deficiencies in the reconstruction of the two-body reduced density matrix (2RDM). We now deduce essential features of an N-electron functional from a wavefunction Ansatz: The extension of the two-electron Löwdin-Shull wavefunction to the N-electron case informs about the phase information. In this paper, applications of this extended Löwdin-Shull (ELS) functional are considered for the simplest case, ELS(1): one (dissociating) two-electron bond in the field of occupied (including core) orbitals. ELS(1) produces high quality ω α (R) curves along the bond dissociation coordinate R for the molecules LiH, Li 2 , and BH with the two outer valence electrons correlated. All of these results indicate that response properties are much more sensitive to deficiencies in the reconstruction of the 2RDM than the ground state energy, since derivatives of the functional with respect to both the NOs and the occupation numbers need to be accurate
Evaluation of response matrix of a multisphere neutron spectrometer ...
Indian Academy of Sciences (India)
Abstract. Neutron energy responses of water sphere spectrometers (WSS) to 30 MeV have been calculated by means of Monte Carlo calculations, using the computer code MCNP4C with ENDF/. B-VI.0 neutron cross-section. The calculations have been performed for 3He detector (typical SP9) placed inside 2, 3, 5, 8, ...
International Nuclear Information System (INIS)
El Bitar, Z; Pino, F; Candela, C; Ros, D; Pavía, J; Rannou, F R; Ruibal, A; Aguiar, P
2014-01-01
It is well-known that in pinhole SPECT (single-photon-emission computed tomography), iterative reconstruction methods including accurate estimations of the system response matrix can lead to submillimeter spatial resolution. There are two different methods for obtaining the system response matrix: those that model the system analytically using an approach including an experimental characterization of the detector response, and those that make use of Monte Carlo simulations. Methods based on analytical approaches are faster and handle the statistical noise better than those based on Monte Carlo simulations, but they require tedious experimental measurements of the detector response. One suggested approach for avoiding an experimental characterization, circumventing the problem of statistical noise introduced by Monte Carlo simulations, is to perform an analytical computation of the system response matrix combined with a Monte Carlo characterization of the detector response. Our findings showed that this approach can achieve high spatial resolution similar to that obtained when the system response matrix computation includes an experimental characterization. Furthermore, we have shown that using simulated detector responses has the advantage of yielding a precise estimate of the shift between the point of entry of the photon beam into the detector and the point of interaction inside the detector. Considering this, it was possible to slightly improve the spatial resolution in the edge of the field of view. (paper)
Response matrix of a multisphere neutron spectrometer with an 3 He proportional counter
International Nuclear Information System (INIS)
Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M.; Mercado S, G.A.
2005-01-01
The response matrix of a Bonner sphere spectrometer was calculated by use of the MCNP code. As thermal neutron counter, the spectrometer has a 3.2 cm-diameter 3 He-filled proportional counter which is located at the center of a set of polyethylene spheres. The response was calculated for 0, 3, 5, 6, 8, 10, 12, and 16 inches-diameter polyethylene spheres for neutrons whose energy goes from 10 -9 to 20 MeV. The response matrix was compared with a set of responses measured with several monoenergetic neutron sources. In this comparison the calculated matrix agrees with the experimental results. The matrix was also compared with the response matrix calculated for the PTB C spectrometer. Even though that calculation was carried out using a detailed model to describe the proportional counter; both matrices do agree, but small differences are observed in the bare case because of the difference in the model used during calculations. Other differences are in some spheres for 14.8 and 20 MeV neutrons, probably due to the differences in the cross sections used during both calculations. (Author) 28 refs., 1 tab., 6 figs
Preconditioned Krylov and Gauss-Seidel solutions of response matrix equations
International Nuclear Information System (INIS)
Lewis, E.E.; Smith, M.A.; Yang, W.S.; Wollaber, A.
2011-01-01
The use of preconditioned Krylov methods is examined as an alternative to the partitioned matrix acceleration applied to red-black Gauss Seidel (RBGS) iteration that is presently used in the variational nodal code, VARIANT. We employ the GMRES algorithm to treat non-symmetric response matrix equations. A pre conditioner is formulated for the within-group diffusion equation which is equivalent to partitioned matrix acceleration of RBGS iterations. We employ the pre conditioner, which closely parallels two-level p multigrid, to improve RBGS and GMRES algorithms. Of the accelerated algorithms, GMRES converges with less computational effort than RBGS and therefore is chosen for further development. The p multigrid pre conditioner requires response matrices with two or more degrees of freedom (DOF) per interface that are polynomials, which are both orthogonal and hierarchical. It is therefore not directly applicable to very fine mesh calculations that are both slow to converge and that are often modeled with response matrices with only one DOF per interface. Orthogonal matrix aggregation (OMA) is introduced to circumvent this difficulty by combining N×N fine mesh response matrices with one DOF per interface into a coarse mesh response matrix with N orthogonal DOF per interface. Numerical results show that OMA used alone or in combination with p multigrid preconditioning substantially accelerates GMRES solutions. (author)
Preconditioned Krylov and Gauss-Seidel solutions of response matrix equations
Energy Technology Data Exchange (ETDEWEB)
Lewis, E.E., E-mail: e-lewis@northwestern.edu [Department of Mechanical Engineering, Northwestern University, Evanston, IL (United States); Smith, M.A.; Yang, W.S.; Wollaber, A., E-mail: masmith@anl.gov, E-mail: wsyang@anl.gov, E-mail: wollaber@lanl.gov [Nuclear Engineering Division, Argonne National Laboratory, Argonne, IL (United States)
2011-07-01
The use of preconditioned Krylov methods is examined as an alternative to the partitioned matrix acceleration applied to red-black Gauss Seidel (RBGS) iteration that is presently used in the variational nodal code, VARIANT. We employ the GMRES algorithm to treat non-symmetric response matrix equations. A pre conditioner is formulated for the within-group diffusion equation which is equivalent to partitioned matrix acceleration of RBGS iterations. We employ the pre conditioner, which closely parallels two-level p multigrid, to improve RBGS and GMRES algorithms. Of the accelerated algorithms, GMRES converges with less computational effort than RBGS and therefore is chosen for further development. The p multigrid pre conditioner requires response matrices with two or more degrees of freedom (DOF) per interface that are polynomials, which are both orthogonal and hierarchical. It is therefore not directly applicable to very fine mesh calculations that are both slow to converge and that are often modeled with response matrices with only one DOF per interface. Orthogonal matrix aggregation (OMA) is introduced to circumvent this difficulty by combining N×N fine mesh response matrices with one DOF per interface into a coarse mesh response matrix with N orthogonal DOF per interface. Numerical results show that OMA used alone or in combination with p multigrid preconditioning substantially accelerates GMRES solutions. (author)
Cavolina, J. M.; Evans, G. L.; Harris, S. A.; Zhang, M.; Westerlind, K. C.; Turner, R. T.
1997-01-01
A 14-day orbital spaceflight was performed using ovariectomized Fisher 344 rats to determine the combined effects of estrogen deficiency and near weightlessness on tibia radial bone growth and cancellous bone turnover. Twelve ovariectomized rats with established cancellous osteopenia were flown aboard the space shuttle Columbia (STS-62). Thirty ovariectomized rats were housed on earth as ground controls: 12 in animal enclosure modules, 12 in vivarium cages, and 6 killed the day of launch for baseline measurements. An additional 18 ovary-intact rats were housed in vivarium cages as ground controls: 8 rats were killed as baseline controls and the remaining 10 rats were killed 14 days later. Ovariectomy increased periosteal bone formation at the tibia-fibula synostosis; cancellous bone resorption and formation in the secondary spongiosa of the proximal tibial metaphysis; and messenger RNA (mRNA) levels for the prepro-alpha2(1) subunit of type 1 collagen, osteocalcin, transforming growth factor-beta, and insulin-like growth factor I in the contralateral proximal tibial metaphysis and for the collagen subunit in periosteum pooled from tibiae and femora and decreased cancellous bone area. Compared to ovariectomized weight-bearing rats, the flight group experienced decreases in periosteal bone formation, collagen subunit mRNA levels, and cancellous bone area. The flight rats had a small decrease in the cancellous mineral apposition rate, but no change in the calculated bone formation rate. Also, spaceflight had no effect on cancellous osteoblast and osteoclast perimeters or on mRNA levels for bone matrix proteins and signaling peptides. On the other hand, spaceflight resulted in an increase in bone resorption, as ascertained from the diminished retention of a preflight fluorochrome label. This latter finding suggests that osteoclast activity was increased. In a follow-up ground-based experiment, unilateral sciatic neurotomy of ovariectomized rats resulted in cancellous
Estimation of the Rotational Terms of the Dynamic Response Matrix
Directory of Open Access Journals (Sweden)
D. Montalvão
2004-01-01
Full Text Available The dynamic response of a structure can be described by both its translational and rotational receptances. The latter ones are frequently not considered because of the difficulties in applying a pure moment excitation or in measuring rotations. However, in general, this implies a reduction up to 75% of the complete model. On the other hand, if a modification includes a rotational inertia, the rotational receptances of the unmodified system are needed. In one method, more commonly found in the literature, a so called T-block is attached to the structure. Then, a force, applied to an arm of the T-block, generates a moment together with a force at the connection point. The T-block also allows for angular displacement measurements. Nevertheless, the results are often not quite satisfactory. In this work, an alternative method based upon coupling techniques is developed, in which rotational receptances are estimated without the need of applying a moment excitation. This is accomplished by introducing a rotational inertia modification when rotating the T-block. The force is then applied in its centroid. Several numerical and experimental examples are discussed so that the methodology can be clearly described. The advantages and limitations are identified within the practical application of the method.
Massively parallel red-black algorithms for x-y-z response matrix equations
International Nuclear Information System (INIS)
Hanebutte, U.R.; Laurin-Kovitz, K.; Lewis, E.E.
1992-01-01
Recently, both discrete ordinates and spherical harmonic (S n and P n ) methods have been cast in the form of response matrices. In x-y geometry, massively parallel algorithms have been developed to solve the resulting response matrix equations on the Connection Machine family of parallel computers, the CM-2, CM-200, and CM-5. These algorithms utilize two-cycle iteration on a red-black checkerboard. In this work we examine the use of massively parallel red-black algorithms to solve response matric equations in three dimensions. This longer term objective is to utilize massively parallel algorithms to solve S n and/or P n response matrix problems. In this exploratory examination, however, we consider the simple 6 x 6 response matrices that are derivable from fine-mesh diffusion approximations in three dimensions
Thermal response of an aeroassisted orbital-transfer vehicle with a conical drag brake
Pitts, W. C.; Murbach, M. S.
1984-01-01
As an aeroassisted orbital-transfer vehicle (AOTV) goes through an aerobraking maneuver, a significant amount of heat is generated. In this paper, the thermal response of a specific AOTV to this aerobrake heating is examined. The vehicle has a 70 deg, conical drag-brake heat shield attached to a cylindrical body which contains the payload. The heat shield is made of silica fabric. The heat-shield thickness is varied from that of a thin cloth to a 1.5-cm blanket. The fabric thickness, the radiation absorptivity of the vehicle surface materials, and radiation from the wake are all significant parameters in the thermal response to the heating produced by the braking maneuver. The maximum temperatures occur in the vicinity of the interface between the body and the conical heat shield.
Thermal Response of an Aeroassisted Orbital Transfer Vehicle with a Conical Drag Brake
Pitts, W. C.; Murbach, M. S.
1985-01-01
As an aeroassisted orbital transfer vehicle (AOTV) goes through an aerobraking maneuver a significant amount of heat is generated. In this paper, the thermal response of a specific AOTV to this aerobrake heating is examined. The vehicle has a 70-deg, Conical drag-brake heat shield attached to a cylindrical body which contains the payload. The heat shield is made of ceramic fabric its thickness is varied from that of a thin cloth to a 1.5-cm blanket. The fabric thickness, the radiation absorptivity of the vehicle surface materials, and radiation from the wake are all significant parameters in the thermal response to the heating produced by the braking maneuver. The maximum temperatures occur In the vicinity of the interface between the body and the conical heat shield.
Evaluation of the global orbit correction algorithm for the APS real-time orbit feedback system
International Nuclear Information System (INIS)
Carwardine, J.; Evans, K. Jr.
1997-01-01
The APS real-time orbit feedback system uses 38 correctors per plane and has available up to 320 rf beam position monitors. Orbit correction is implemented using multiple digital signal processors. Singular value decomposition is used to generate a correction matrix from a linear response matrix model of the storage ring lattice. This paper evaluates the performance of the APS system in terms of its ability to correct localized and distributed sources of orbit motion. The impact of regulator gain and bandwidth, choice of beam position monitors, and corrector dynamics are discussed. The weighted least-squares algorithm is reviewed in the context of local feedback
van Meer, R; Gritsenko, O V; Baerends, E J
2018-03-14
Almost all functionals that are currently used in density matrix functional theory have been created by some a priori ansatz that generates approximations to the second-order reduced density matrix (2RDM). In this paper, a more consistent approach is used: we analyze the 2RDMs (in the natural orbital basis) of rather accurate multi-reference configuration interaction expansions for several small molecules (CH 4 , NH 3 , H 2 O, FH, and N 2 ) and use the knowledge gained to generate new functionals. The analysis shows that a geminal-like structure is present in the 2RDMs, even though no geminal theory has been applied from the onset. It is also shown that the leading non-geminal dynamical correlation contributions are generated by a specific set of double excitations. The corresponding determinants give rise to non-JKL (non Coulomb/Exchange like) multipole-multipole dispersive attractive terms between geminals. Due to the proximity of the geminals, these dispersion terms are large and cannot be omitted, proving pure JKL functionals to be essentially deficient. A second correction emerges from the observation that the "normal" geminal-like exchange between geminals breaks down when one breaks multiple bonds. This problem can be fixed by doubling the exchange between bond broken geminals, effectively restoring the often physically correct high-spin configurations on the bond broken fragments. Both of these corrections have been added to the commonly used antisymmetrized product of strongly orthogonal geminals functional. The resulting non-JKL functional Extended Löwdin-Shull Dynamical-Multibond is capable of reproducing complete active space self-consistent field curves, in which one active orbital is used for each valence electron.
van Meer, R.; Gritsenko, O. V.; Baerends, E. J.
2018-03-01
Almost all functionals that are currently used in density matrix functional theory have been created by some a priori ansatz that generates approximations to the second-order reduced density matrix (2RDM). In this paper, a more consistent approach is used: we analyze the 2RDMs (in the natural orbital basis) of rather accurate multi-reference configuration interaction expansions for several small molecules (CH4, NH3, H2O, FH, and N2) and use the knowledge gained to generate new functionals. The analysis shows that a geminal-like structure is present in the 2RDMs, even though no geminal theory has been applied from the onset. It is also shown that the leading non-geminal dynamical correlation contributions are generated by a specific set of double excitations. The corresponding determinants give rise to non-JKL (non Coulomb/Exchange like) multipole-multipole dispersive attractive terms between geminals. Due to the proximity of the geminals, these dispersion terms are large and cannot be omitted, proving pure JKL functionals to be essentially deficient. A second correction emerges from the observation that the "normal" geminal-like exchange between geminals breaks down when one breaks multiple bonds. This problem can be fixed by doubling the exchange between bond broken geminals, effectively restoring the often physically correct high-spin configurations on the bond broken fragments. Both of these corrections have been added to the commonly used antisymmetrized product of strongly orthogonal geminals functional. The resulting non-JKL functional Extended Löwdin-Shull Dynamical-Multibond is capable of reproducing complete active space self-consistent field curves, in which one active orbital is used for each valence electron.
Starke, J.; Wehrle-Haller, B.; Friedl, P.
2014-01-01
Mobile cells discriminate and adapt to mechanosensory input from extracellular matrix (ECM) topographies to undergo actin-based polarization, shape change and migration. We tested 'cell-intrinsic' and adaptive components of actin-based cell migration in response to widely used in vitro
Optical-limiting response of rare-earth metallo-phthalocyanine-doped copolymer matrix
Aneeshkumar, B.N.; Gopinath, P.; Vallabhan, C.P.G.; Nampoori, V.P.N.; Radhakrishnan, P.; Thomas, J.
2003-01-01
The nanosecond optical-limiting characteristics (at 532 nm) of some rare-earth metallo-phthalocyanines (Sm(Pc)2, Eu(Pc)2, and LaPc) doped in a copolymer matrix of poly(Me methacrylate) and Me-2-cyanoacrylate were studied for the 1st time to the authors' knowledge. The optical-limiting response is
Jochum, M.; Peacock, S.; Moore, J. K.; Lindsay, K. T.
2009-12-01
A global general circulation model coupled to an ocean ecosystem model is used to quantify the response of carbon fluxes and climate to changes in orbital forcing. Compared to the present-day simulation, the simulation with the Earth's orbital parameters from 115,000 years ago features significantly cooler northern high latitudes, but only moderately cooler southern high latitudes. This asymmetry is explained by a 30% reduction of the strength of the Atlantic Meridional Overturning Circulation that is caused by an increased Arctic sea-ice export and a resulting freshening of the North Atlantic. The strong northern high-latitude cooling and the direct insolation induced tropical warming lead to global shifts in precipitation and winds to the order of 10-20%. These climate shifts lead to regional differences in air-sea carbon fluxes of the same order. However, the differences in global net carbon fluxes are insignificant. This surprising result is due to several effects, two of which stand out: Firstly, colder sea surface temperature leads to a more effective solubility pump but also to increased sea-ice concentration which blocks air-sea exchange; and secondly, the weakening of Southern Ocean winds, which is predicted by some idealized studies, is small compared to its interannual variability.
Directory of Open Access Journals (Sweden)
Andrej Kansky
2002-12-01
Full Text Available Background. Orbit is involved in 40% of all facial fractures. There is considerable variety in severity, ranging from simple nondisplaced to complex comminuted fractures. Complex comminuted fractures (up to 20% are responsible for the majority of complications and unfavorable results. Orbital fractures are classified as internal orbital fractures, zygomatico-orbital fractures, naso-orbito-ethmoidal fractures and combined fractures. The ophtalmic sequelae of midfacial fractures are usually edema and ecchymosis of the soft tissues, subconjuctival hemorrhage, diplopia, iritis, retinal edema, ptosis, enophthalmos, ocular muscle paresis, mechanical restriction of ocular movement and nasolacrimal disturbances. More severe injuries such as optic nerve trauma and retinal detachments have also been reported. Within the wide range of orbital fractures small group of complex fractures causes most of the sequelae. Therefore identification of severe injuries and adequate treatment is of major importance. The introduction of craniofacial techniques made possible a wide exposure even of large orbital wall defects and their reconstruction by bone grafts. In spite of significant progress, repair of complex orbital wall defects remains a problem even for the experienced surgeons.Results. In 1999 121 facial injuries were treated at our department (Clinical Centre Ljubljana Dept. Of Maxillofacial and Oral Surgery. Orbit was involved in 65% of cases. Isolated inner orbital fractures presented 4% of all fractures. 17 (14% complex cases were treated, 5 of them being NOE, 5 orbital (frame and inner walls, 3 zygomatico-orbital, 2 FNO and 2 maxillo-orbital fractures.Conclusions. Final result of the surgical treatment depends on severity of maxillofacial trauma. Complex comminuted fractures are responsable for most of the unfavorable results and ocular function is often permanently damaged (up to 75% in these fractures.
Physiological responses of astronaut candidates to simulated +Gx orbital emergency re-entry.
Wu, Bin; Xue, Yueying; Wu, Ping; Gu, Zhiming; Wang, Yue; Jing, Xiaolu
2012-08-01
We investigated astronaut candidates' physiological and pathological responses to +Gx exposure during simulated emergency return from a running orbit to advance astronaut +Gx tolerance training and medical support in manned spaceflight. There were 13 male astronaut candidates who were exposed to a simulated high +Gx acceleration profile in a spacecraft during an emergency return lasting for 230 s. The peak value was 8.5 G. Subjective feelings and symptoms, cardiovascular and respiratory responses, and changes in urine component before, during, and after +Gx exposure were investigated. Under high +Gx exposure, 15.4% of subjects exhibited arrhythmia. Heart rate (HR) increased significantly and four different types of HR response curves were distinguished. The ratio of QT to RR interval on the electrocardiograms was significantly increased. Arterial oxygen saturation (SaO2) declined with increasing G value and then returned gradually. SaO2 reached a minimum (87.7%) at 3 G during the decline phase of the +Gx curve. Respiratory rate increased significantly with increasing G value, while the amplitude and area of the respiratory waves were significantly reduced. The overshoot appeared immediately after +Gx exposure. A few subjects suffered from slight injuries, including positive urine protein (1/13), positive urinary occult blood (1/13), and a large area of petechiae on the back (1/13). Astronaut candidates have relatively good tolerance to the +Gx profile during a simulation of spacecraft emergent ballistic re-entry. However, a few subjects exhibited adverse physiological responses and slight reversible pathological injuries.
Use of eigenvectors in understanding and correcting storage ring orbits
International Nuclear Information System (INIS)
Friedman, A.; Bozoki, E.
1994-01-01
The response matrix A is defined by the equation X=AΘ, where Θ is the kick vector and X is the resulting orbit vector. Since A is not necessarily a symmetric or even a square matrix we symmetrize it by using A T A. Then we find the eigenvalues and eigenvectors of this A T A matrix. The physical interpretation of the eigenvectors for circular machines is discussed. The task of the orbit correction is to find the kick vector Θ for a given measured orbit vector X. We are presenting a method, in which the kick vector is expressed as linear combination of the eigenvectors. An additional advantage of this method is that it yields the smallest possible kick vector to correct the orbit. We will illustrate the application of the method to the NSLS X-ray and UV storage rings and the resulting measurements. It will be evident, that the accuracy of this method allows the combination of the global orbit correction and local optimization of the orbit for beam lines and insertion devices. The eigenvector decomposition can also be used for optimizing kick vectors, taking advantage of the fact that eigenvectors with corresponding small eigenvalue generate negligible orbit changes. Thus, one can reduce a kick vector calculated by any other correction method and still stay within the tolerance for orbit correction. The use of eigenvectors in accurately measuring the response matrix and the use of the eigenvalue decomposition orbit correction algorithm in digital feedback is discussed. (orig.)
Directory of Open Access Journals (Sweden)
Liu Qimao
2018-02-01
Full Text Available This paper proposes an assumption that the fibre is elastic material and polymer matrix is viscoelastic material so that the energy dissipation depends only on the polymer matrix in dynamic response process. The damping force vectors in frequency and time domains, of FRP (Fibre-Reinforced Polymer matrix laminated composite plates, are derived based on this assumption. The governing equations of FRP laminated composite plates are formulated in both frequency and time domains. The direct inversion method and direct time integration method for nonviscously damped systems are employed to solve the governing equations and achieve the dynamic responses in frequency and time domains, respectively. The computational procedure is given in detail. Finally, dynamic responses (frequency responses with nonzero and zero initial conditions, free vibration, forced vibrations with nonzero and zero initial conditions of a FRP laminated composite plate are computed using the proposed methodology. The proposed methodology in this paper is easy to be inserted into the commercial finite element analysis software. The proposed assumption, based on the theory of material mechanics, needs to be further proved by experiment technique in the future.
Liu, Qimao
2018-02-01
This paper proposes an assumption that the fibre is elastic material and polymer matrix is viscoelastic material so that the energy dissipation depends only on the polymer matrix in dynamic response process. The damping force vectors in frequency and time domains, of FRP (Fibre-Reinforced Polymer matrix) laminated composite plates, are derived based on this assumption. The governing equations of FRP laminated composite plates are formulated in both frequency and time domains. The direct inversion method and direct time integration method for nonviscously damped systems are employed to solve the governing equations and achieve the dynamic responses in frequency and time domains, respectively. The computational procedure is given in detail. Finally, dynamic responses (frequency responses with nonzero and zero initial conditions, free vibration, forced vibrations with nonzero and zero initial conditions) of a FRP laminated composite plate are computed using the proposed methodology. The proposed methodology in this paper is easy to be inserted into the commercial finite element analysis software. The proposed assumption, based on the theory of material mechanics, needs to be further proved by experiment technique in the future.
A 222 energy bins response matrix for a {sup 6}Lil scintillator Bss system
Energy Technology Data Exchange (ETDEWEB)
Lacerda, M. A. S. [Centro de Desenvolvimento da Tecnologia Nuclear, Laboratorio de Calibracao de Dosimetros, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Mendez V, R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Laboratorio de Patrones Neutronicos, Av. Complutense 22, 28040 Madrid (Spain); Lorente F, A.; Ibanez F, S.; Gallego D, E., E-mail: masl@cdtn.br [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, 28006 Madrid (Spain)
2016-10-15
A new response matrix was calculated for a Bonner Sphere Spectrometer (Bss) with a {sup 6}Lil(Eu) scintillator. We utilized the Monte Carlo N-particle radiation transport code MCNPX, version 2.7.0, with Endf/B-VII.0 nuclear data library to calculate the responses for 6 spheres and the bare detector, for energies varying from 9.441 E(-10) MeV to 105.9 MeV, with 20 equal-log(E)-width bins per energy decade, totalizing 222 energy groups. A Bss, like the modeled in this work, was utilized to measure the neutron spectrum generated by the {sup 241}AmBe source of the Universidad Politecnica de Madrid. From the count rates obtained with this Bss system we unfolded neutron spectrum utilizing the BUNKIUT code for 31 energy bins (UTA-4 response matrix) and the MAXED code with the new calculated response functions. We compared spectra obtained with these Bss system / unfold codes with that obtained from measurements performed with a Bss system constituted of 12 spheres with a spherical {sup 3}He Sp-9 counter (Centronic Ltd., UK) and MAXED code with the system-specific response functions (Bss-CIEMAT). A relatively good agreement was observed between our response matrix and that calculated by other authors. In general, we observed an improvement in the agreement as the energy increases. However, higher discrepancies were observed for energies close to 1-E(-8) MeV and, mainly, for energies above 20 MeV. These discrepancies were mainly attributed to the differences in cross-section libraries employed. The ambient dose equivalent (H (10)) calculated with the {sup 6}Lil-MAXED showed a good agreement with values measured with the neutron area monitor Bert hold Lb 6411 and within 12% the value obtained with another Bss system (Bss-CIEMAT). The response matrix calculated in this work can be utilized together with the MAXED code to generate neutron spectra with a good energy resolution up to 20 MeV. Some additional tests are being done to validate this response matrix and improve the
A 222 energy bins response matrix for a "6Lil scintillator Bss system
International Nuclear Information System (INIS)
Lacerda, M. A. S.; Vega C, H. R.; Mendez V, R.; Lorente F, A.; Ibanez F, S.; Gallego D, E.
2016-10-01
A new response matrix was calculated for a Bonner Sphere Spectrometer (Bss) with a "6Lil(Eu) scintillator. We utilized the Monte Carlo N-particle radiation transport code MCNPX, version 2.7.0, with Endf/B-VII.0 nuclear data library to calculate the responses for 6 spheres and the bare detector, for energies varying from 9.441 E(-10) MeV to 105.9 MeV, with 20 equal-log(E)-width bins per energy decade, totalizing 222 energy groups. A Bss, like the modeled in this work, was utilized to measure the neutron spectrum generated by the "2"4"1AmBe source of the Universidad Politecnica de Madrid. From the count rates obtained with this Bss system we unfolded neutron spectrum utilizing the BUNKIUT code for 31 energy bins (UTA-4 response matrix) and the MAXED code with the new calculated response functions. We compared spectra obtained with these Bss system / unfold codes with that obtained from measurements performed with a Bss system constituted of 12 spheres with a spherical "3He Sp-9 counter (Centronic Ltd., UK) and MAXED code with the system-specific response functions (Bss-CIEMAT). A relatively good agreement was observed between our response matrix and that calculated by other authors. In general, we observed an improvement in the agreement as the energy increases. However, higher discrepancies were observed for energies close to 1-E(-8) MeV and, mainly, for energies above 20 MeV. These discrepancies were mainly attributed to the differences in cross-section libraries employed. The ambient dose equivalent (H (10)) calculated with the "6Lil-MAXED showed a good agreement with values measured with the neutron area monitor Bert hold Lb 6411 and within 12% the value obtained with another Bss system (Bss-CIEMAT). The response matrix calculated in this work can be utilized together with the MAXED code to generate neutron spectra with a good energy resolution up to 20 MeV. Some additional tests are being done to validate this response matrix and improve the results for energies
Response matrix calculation of a Bonner Sphere Spectrometer using ENDF/B-VII libraries
Energy Technology Data Exchange (ETDEWEB)
Morató, Sergio; Juste, Belén; Miró, Rafael; Verdú, Gumersindo [Instituto de Seguridad Industrial, Radiofísica y Medioambiental (ISIRYM), Universitat Politècnica de València (Spain); Guardia, Vicent, E-mail: bejusvi@iqn.upv.es [GD Energy Services, Valencia (Spain). Grupo dominguis
2017-07-01
The present work is focused on the reconstruction of a neutron spectra using a multisphere spectrometer also called Bonner Spheres System (BSS). To that, the determination of the response detector curves is necessary therefore we have obtained the response matrix of a neutron detector by Monte Carlo (MC) simulation with MCNP6 where the use of unstructured mesh geometries is introduced as a novelty. The aim of these curves was to study the theoretical response of a widespread neutron spectrometer exposed to neutron radiation. A neutron detector device has been used in this work which is formed by a multispheres spectrometer (BSS) that uses 6 high density polyethylene spheres with different diameters. The BSS consists of a set of 0.95 g/cm{sup 3} high density polyethylene spheres. The detector is composed of a lithium iodide 6LiI cylindrical scintillator crystal 4mm x 4mm size LUDLUM Model 42 coupled to a photomultiplier tube. Thermal tables are required to include polyethylene cross section in the simulation. These data are essential to get correct and accurate results in problems involving neutron thermalization. Nowadays available literature present the response matrix calculated with ENDF.B.V cross section libraries (V.Mares et al 1993) or with ENDF.B.VI (R.Vega Carrillo et al 2007). This work uses two novelties to calculate the response matrix. On the one hand the use of unstructured meshes to simulate the geometry of the detector and the Bonner Spheres and on the other hand the use of the updated ENDF.B.VII cross sections libraries. A set of simulations have been performed to obtain the detector response matrix. 29 mono energetic neutron beams between 10 KeV to 20 MeV were used as source for each moderator sphere up to a total of 174 simulations. Each mono energetic source was defined with the same diameter as the moderating sphere used in its corresponding simulation and the spheres were uniformly irradiated from the top of the photomultiplier tube. Some
ON-LINE NONLINEAR CHROMATICITY CORRECTION USING OFF-MOMENTUM TUNE RESPONSE MATRIX
International Nuclear Information System (INIS)
LUO, Y.; FISCHER, W.; MALISKY, N.; TEPIKIAN, S.; TROBJEVIC, D.
2007-01-01
In this article, we propose a method for the online nonlinear chromaticity correction at store in the Relativistic Heavy Ion Collider (RHIC). With 8 arc sextupole families in each RHIC ring, the nonlinear chromaticities can be minimized online by matching the off-momentum tunes onto the wanted tunes given by the linear chromaticities. The Newton method is used for this multi-dimensional nonlinear optimization, where the off-momentum tune response matrix with respect to sextupole strength changes is adopted. The off-momentum tune response matrix can be calculated with the online accelerator optics model or directly measured with the real beam. In this article, the correction algorithm for the RHIC is presented. Simulations are also carried out to verify the method. The preliminary results from the beam experiments taken place in the RHIC 2007 Au run are reviewed
Solution of the Multigroup-Diffusion equation by the response matrix method
International Nuclear Information System (INIS)
Oliveira, C.R.E.
1980-10-01
A preliminary analysis of the response matrix method is made, considering its application to the solution of the multigroup diffusion equations. The one-dimensional formulation is presented and used to test some flux expansions, seeking the application of the method to the two-dimensional problem. This formulation also solves the equations that arise from the integro-differential synthesis algorithm. The slow convergence of the power method, used to solve the eigenvalue problem, and its acceleration by means of the Chebyshev polynomial method, are also studied. An algorithm for the estimation of the dominance ratio is presented, based on the residues of two successive iteration vectors. This ratio, which is not known a priori, is fundamental for the efficiency of the method. Some numerical problems are solved, testing the 1D formulation of the response matrix method, its application to the synthesis algorithm and also, at the same time, the algorithm to accelerate the source problem. (Author) [pt
Nonlinear mechanical response of the extracellular matrix: learning from articular cartilage
Kearns, Sarah; Das, Moumita
2015-03-01
We study the mechanical structure-function relations in the extracellular matrix (ECM) with focus on nonlinear shear and compression response. As a model system, our study focuses on the ECM in articular cartilage tissue which has two major mechanobiological components: a network of the biopolymer collagen that acts as a stiff, reinforcing matrix, and a flexible aggrecan network that facilitates deformability. We model this system as a double network hydrogel made of interpenetrating networks of stiff and flexible biopolymers respectively. We study the linear and nonlinear mechanical response of the model ECM to shear and compression forces using a combination of rigidity percolation theory and energy minimization approaches. Our results may provide useful insights into the design principles of the ECM as well as biomimetic hydrogels that are mechanically robust and can, at the same time, easily adapt to cues in their surroundings.
A massively parallel discrete ordinates response matrix method for neutron transport
International Nuclear Information System (INIS)
Hanebutte, U.R.; Lewis, E.E.
1992-01-01
In this paper a discrete ordinates response matrix method is formulated with anisotropic scattering for the solution of neutron transport problems on massively parallel computers. The response matrix formulation eliminates iteration on the scattering source. The nodal matrices that result from the diamond-differenced equations are utilized in a factored form that minimizes memory requirements and significantly reduces the number of arithmetic operations required per node. The red-black solution algorithm utilizes massive parallelism by assigning each spatial node to one or more processors. The algorithm is accelerated by a synthetic method in which the low-order diffusion equations are also solved by massively parallel red-black iterations. The method is implemented on a 16K Connection Machine-2, and S 8 and S 16 solutions are obtained for fixed-source benchmark problems in x-y geometry
Reactor calculation in coarse mesh by finite element method applied to matrix response method
International Nuclear Information System (INIS)
Nakata, H.
1982-01-01
The finite element method is applied to the solution of the modified formulation of the matrix-response method aiming to do reactor calculations in coarse mesh. Good results are obtained with a short running time. The method is applicable to problems where the heterogeneity is predominant and to problems of evolution in coarse meshes where the burnup is variable in one same coarse mesh, making the cross section vary spatially with the evolution. (E.G.) [pt
IMMUNE RESPONSE TO EXTRACELLULAR MATRIX COLLAGEN IN CHRONIC HEPATITIS C INDUCED LIVER FIBROSIS
Borg, Brian B.; Seetharam, Anil; Subramanian, Vijay; Ilias, Haseeb; Lisker–Melman, Mauricio; Korenblat, Kevin; Anderson, Christopher; Shenoy, Surendra; Chapman, William C.; Crippin, Jeffrey S.; Mohanakumar, Thalachallour
2011-01-01
Hepatitis C Virus (HCV) infection and recurrence post-transplant (OLT) is associated with extracellular matrix (ECM) components remodeling, particularly collagen (Col), leading to fibrosis. Our aim was to determine whether development of antibodies (Abs) to self antigen Col in HCV infection correlates with fibrosis stage and peripheral cytokine response. Chronic HCV patients, those with recurrence after OLT undergoing biopsy and healthy control subjects were enrolled. HCV subjects (n=70) were...
The response-matrix based AFEN method for the hexagonal geometry
International Nuclear Information System (INIS)
Noh, Jae Man; Kim, Keung Koo; Zee, Sung Quun; Joo, Hyung Kook; Cho, Byng Oh; Jeong, Hyung Guk; Cho, Jin Young
1998-03-01
The analytic function expansion nodal (AFEN) method, developed to overcome the limitations caused by the transverse integration, has been successfully to predict the neutron behavior in the hexagonal core as well as rectangular core. In the hexagonal node, the transverse leakage resulted from the transverse integration has some singular terms such as delta-function and step-functions near the node center line. In most nodal methods using the transverse integration, the accuracy of nodal method is degraded because the transverse leakage is approximated as a smooth function across the node center line by ignoring singular terms. However, the AFEN method in which there is no transverse leakage term in deriving nodal coupling equations keeps good accuracy for hexagonal node. In this study, the AFEN method which shows excellent accuracy in the hexagonal core analyses is reformulated as a response matrix form. This form of the AFEN method can be implemented easily to nodal codes based on the response matrix method. Therefore, the Coarse Mesh Rebalance (CMR) acceleration technique which is one of main advantages of the response matrix method can be utilized for the AFEN method. The response matrix based AFEN method has been successfully implemented into the MASTER code and its accuracy and computational efficiency were examined by analyzing the two- and three- dimensional benchmark problem of VVER-440. Based on the results, it can be concluded that the newly formulated AFEN method predicts accurately the assembly powers (within 0.2% average error) as well as the effective multiplication factor (within 0.2% average error) as well as the effective multiplication factor (within 20 pcm error). In addition, the CMR acceleration technique is quite efficient in reducing the computation time of the AFEN method by 8 to 10 times. (author). 22 refs., 1 tab., 4 figs
Narayanan, Amal; Chandel, Shubham; Ghosh, Nirmalya; De, Priyadarsi
2015-09-15
Probing volume phase transition behavior of superdiluted polymer solutions both micro- and macroscopically still persists as an outstanding challenge. In this regard, we have explored 4 × 4 spectral Mueller matrix measurement and its inverse analysis for excavating the microarchitectural facts about stimuli responsiveness of "smart" polymers. Phase separation behavior of thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) and pH responsive poly(N,N-(dimethylamino)ethyl methacrylate) (PDMAEMA) and their copolymers were analyzed in terms of Mueller matrix derived polarization parameters, namely, depolarization (Δ), diattenuation (d), and linear retardance (δ). The Δ, d, and δ parameters provided useful information on both macro- and microstructural alterations during the phase separation. Additionally, the two step action ((i) breakage of polymer-water hydrogen bonding and (ii) polymer-polymer aggregation) at the molecular microenvironment during the cloud point generation was successfully probed via these parameters. It is demonstrated that, in comparison to the present techniques available for assessing the hydrophobic-hydrophilic switch over of simple stimuli-responsive polymers, Mueller matrix polarimetry offers an important advantage requiring a few hundred times dilute polymer solution (0.01 mg/mL, 1.1-1.4 μM) at a low-volume format.
Orbital-motion-limited theory of dust charging and plasma response
International Nuclear Information System (INIS)
Tang, Xian-Zhu; Luca Delzanno, Gian
2014-01-01
The foundational theory for dusty plasmas is the dust charging theory that provides the dust potential and charge arising from the dust interaction with a plasma. The most widely used dust charging theory for negatively charged dust particles is the so-called orbital motion limited (OML) theory, which predicts the dust potential and heat collection accurately for a variety of applications, but was previously found to be incapable of evaluating the dust charge and plasma response in any situation. Here, we report a revised OML formulation that is able to predict the plasma response and hence the dust charge. Numerical solutions of the new OML model show that the widely used Whipple approximation of dust charge-potential relationship agrees with OML theory in the limit of small dust radius compared with plasma Debye length, but incurs large (order-unity) deviation from the OML prediction when the dust size becomes comparable with or larger than plasma Debye length. This latter case is expected for the important application of dust particles in a tokamak plasma
Johnson, Laura A.; Rodansky, Eva S.; Sauder, Kay L.; Horowitz, Jeffrey C.; Mih, Justin D.; Tschumperlin, Daniel J.; Higgins, Peter D.
2013-01-01
Background Crohn’s disease is characterized by repeated cycles of inflammation and mucosal healing which ultimately progress to intestinal fibrosis. This inexorable progression towards fibrosis suggests that fibrosis becomes inflammation-independent and auto-propagative. We hypothesized that matrix stiffness regulates this auto-propagation of intestinal fibrosis. Methods The stiffness of fresh ex vivo samples from normal human small intestine, Crohn’s disease strictures, and the unaffected margin were measured with a microelastometer. Normal human colonic fibroblasts were cultured on physiologically normal or pathologically stiff matrices corresponding to the physiological stiffness of normal or fibrotic bowel. Cellular response was assayed for changes in cell morphology, α-smooth muscle actin (αSMA) staining, and gene expression. Results Microelastometer measurements revealed a significant increase in colonic tissue stiffness between normal human colon and Crohn’s strictures as well as between the stricture and adjacent tissue margin. In Ccd-18co cells grown on stiff matrices corresponding to Crohn’s strictures, cellular proliferation increased. Pathologic stiffness induced a marked change in cell morphology and increased αSMA protein expression. Growth on a stiff matrix induced fibrogenic gene expression, decreased matrix metalloproteinase and pro-inflammatory gene expression, and was associated with nuclear localization of the transcriptional cofactor MRTF-A. Conclusions Matrix stiffness, representative of the pathological stiffness of Crohn’s strictures, activates human colonic fibroblasts to a fibrogenic phenotype. Matrix stiffness affects multiple pathways suggesting the mechanical properties of the cellular environment are critical to fibroblast function and may contribute to autopropagation of intestinal fibrosis in the absence of inflammation, thereby contributing to the intractable intestinal fibrosis characteristic of Crohn’s disease. PMID
The relativistic electron response at geosynchronous orbit during the January 1997 magnetic storm
International Nuclear Information System (INIS)
Reeves, G.D.; Friedel, R.H.; Belian, R.D.; Meier, M.M.; Henderson, M.G.; Onsager, T.; Singer, H.J.; Baker, D.N.; Li, X.
1998-01-01
The first geomagnetic storm of 1997 began on January 10. It is of particular interest because it was exceptionally well observed by the full complement of International Solar Terrestrial Physics (ISTP) satellites and because of its possible association with the catastrophic failure of the Telstar 401 telecommunications satellite. Here we report on the energetic electron environment observed by five geosynchronous satellites. In part one of this paper we examine the magnetospheric response to the magnetic cloud. The interval of southward IMF drove strong substorm activity while the interval of northward IMF and high solar wind density strongly compressed the magnetosphere. At energies above a few hundred keV, two distinct electron enhancements were observed at geosynchronous orbit. The first enhancement began and ended suddenly, lasted for approximately 1 day, and is associated with the strong compression of the magnetosphere. The second enhancement showed a more characteristic time delay, peaking on January 15. Both enhancements may be due to transport of electrons from the same initial acceleration event at a location inside geosynchronous orbit but the first enhancement was due to a temporary, quasi-adiabatic transport associated with the compression of the magnetosphere while the second enhancement was due to slower diffusive processes. In the second part of the paper we compare the relativistic electron fluxes measured simultaneously at different local times. We find that the >2-MeV electron fluxes increased first at noon followed by dusk and then dawn and that there can be difference of two orders of magnitude in the fluxes observed at different local times. Finally, we discuss the development of data-driven models of the relativistic electron belts for space weather applications. By interpolating fluxes between satellites we produced a model that gives the >2-MeV electron fluxes at all local times as a function of universal time. In a first application of
Monsoonal response to mid-holocene orbital forcing in a high resolution GCM
Directory of Open Access Journals (Sweden)
J. H. C. Bosmans
2012-04-01
Full Text Available In this study, we use a sophisticated high-resolution atmosphere-ocean coupled climate model, EC-Earth, to investigate the effect of Mid-Holocene orbital forcing on summer monsoons on both hemispheres. During the Mid-Holocene (6 ka, there was more summer insolation on the Northern Hemisphere than today, which intensified the meridional temperature and pressure gradients. Over North Africa, monsoonal precipitation is intensified through increased landward monsoon winds and moisture advection as well as decreased moisture convergence over the oceans and more convergence over land compared to the pre-industrial simulation. Precipitation also extends further north as the ITCZ shifts northward in response to the stronger poleward gradient of insolation. This increase and poleward extent is stronger than in most previous ocean-atmosphere GCM simulations. In north-westernmost Africa, precipitation extends up to 35° N. Over tropical Africa, internal feedbacks completely overcome the direct warming effect of increased insolation. We also find a weakened African Easterly Jet. Over Asia, monsoonal precipitation during the Mid-Holocene is increased as well, but the response is different than over North-Africa. There is more convection over land at the expense of convection over the ocean, but precipitation does not extend further northward, monsoon winds over the ocean are weaker and the surrounding ocean does not provide more moisture. On the Southern Hemisphere, summer insolation and the poleward insolation gradient were weaker during the Mid-Holocene, resulting in a reduced South American monsoon through decreased monsoon winds and less convection, as well as an equatorward shift in the ITCZ. This study corroborates the findings of paleodata research as well as previous model studies, while giving a more detailed account of Mid-Holocene monsoons.
Response of energetic particles to local magnetic dipolarization inside geosynchronous orbit
Motoba, T.; Ohtani, S.; Gkioulidou, M.; Takahashi, K.
2017-12-01
Magnetic field dipolarization and energetic particle injections are the most distinct phenomena observed in the inner magnetosphere during the substorm expansion phase. Compared to a wealth of knowledge about the phenomenology of magnetic dipolarizations and particle injections at/outside geosynchronous orbit (GEO), our understanding of them inside GEO remains incomplete because of a very limited number of previous studies. In the present study, we statistically examine the response of 1-1000 keV energetic particles to local magnetic dipolarization by performing a superposed epoch analysis of energetic particle fluxes with the zero epoch defined as the dipolarization onset times. Based on data from the Van Allen Probes tail seasons in 2012-2016, we identified a total of 97 magnetic dipolarization events which occurred closer to the magnetic equator (i.e., BH, which is antiparallel to the Earth's dipole axis, is the dominant component of the local magnetic field at least for 5 min before the onset). For major ion species (hydrogen, helium, and oxygen ions), the relative flux intensity to the pre-onset level increases at > 50 keV and decreases at inverse energy dispersion. For dipolarizations with strong impulsive westward electric fields, the relative electron flux intensity increases up to 5-10 times, in particular most significant at several tens of keV. This result suggests that the impulsive electric field acts as an efficient factor in the rapid energization of the tens-of-keV electrons. We also discuss how the response of energetic particles to dipolarization depends on MLT, radial distance, and pitch angle.
Response matrix method and its application to SCWR single channel stability analysis
International Nuclear Information System (INIS)
Zhao, Jiyun; Tseng, K.J.; Tso, C.P.
2011-01-01
To simulate the reactor system dynamic features during density wave oscillations (DWO), both the non-linear method and the linear method can be used. Although some transient information is lost through model linearization, the high computational efficiency and relatively accurate results make the linear analysis methodology attractive, especially for prediction of the onset of instability. In the linear stability analysis, the system models are simplified through linearization of the complex non-linear differential equations, and then, the linear differential equations are generally solved in the frequency domain through Laplace transformation. In this paper, a system response matrix method was introduced by directly solving the differential equations in the time domain. By using a system response matrix method, the complicated transfer function derivation, which must be done in the frequency domain method, can be avoided. Using the response matrix method, a model was developed and applied to the single channel or parallel channel type instability analyses of the typical proposed SCWR design. The sensitivity of the decay ratio (DR) to the axial mesh size was analyzed and it was found that the DR is not sensitive to mesh size once sufficient number of axial nodes is applied. To demonstrate the effects of the inlet orificing to the stability feature for the supercritical condition, the sensitivity of the stability to inlet orifice coefficient was conducted for hot channel. It is clearly shown that a higher inlet orifice coefficient will make the system more stable. The susceptibility of stability to operating parameters such as mass flow rate, power and system pressure was also performed. And the measure to improve the SCWR stability sensitivity to operating parameters was investigated. It was found that the SCWR stability sensitivity feature can be improved by carefully managing the inlet orifices and choosing proper operating parameters. (author)
Importance of matrix inelastic deformations in the initial response of magnetic elastomers.
Sánchez, Pedro A; Gundermann, Thomas; Dobroserdova, Alla; Kantorovich, Sofia S; Odenbach, Stefan
2018-03-14
Being able to predict and understand the behaviour of soft magnetic materials paves the way to their technological applications. In this study we analyse the magnetic response of soft magnetic elastomers (SMEs) with magnetically hard particles. We present experimental evidence of a difference between the first and next magnetisation loops exhibited by these SMEs, which depends non-monotonically on the interplay between the rigidity of the polymer matrix, its mechanical coupling with the particles, and the magnetic interactions in the system. In order to explain the microstructural mechanism behind this behaviour, we used a minimal computer simulation model whose results evidence the importance of irreversible matrix deformations due to both translations and rotations of the particles. To confirm the simulation findings, computed tomography (CT) was used. We conclude that the initial exposure to the field triggers the inelastic matrix relaxation in the SMEs, as particles attempt to reorient. However, once the necessary degree of freedom is achieved, both the rotations and the magnetisation behaviour become stationary. We expect this scenario not only to be limited to the materials studied here, but also to apply to a broader class of hybrid SMEs.
MUSIC-type imaging of a thin penetrable inclusion from its multi-static response matrix
International Nuclear Information System (INIS)
Park, Won-Kwang; Lesselier, Dominique
2009-01-01
The imaging of a thin inclusion, with dielectric and/or magnetic contrasts with respect to the embedding homogeneous medium, is investigated. A MUSIC-type algorithm operating at a single time-harmonic frequency is developed in order to map the inclusion (that is, to retrieve its supporting curve) from scattered field data collected within the multi-static response matrix. Numerical experiments carried out for several types of inclusions (dielectric and/or magnetic ones, straight or curved ones), mostly single inclusions and also two of them close by as a straightforward extension, illustrate the pros and cons of the proposed imaging method
Solving Eigenvalue response matrix equations with Jacobian-Free Newton-Krylov methods
International Nuclear Information System (INIS)
Roberts, Jeremy A.; Forget, Benoit
2011-01-01
The response matrix method for reactor eigenvalue problems is motivated as a technique for solving coarse mesh transport equations, and the classical approach of power iteration (PI) for solution is described. The method is then reformulated as a nonlinear system of equations, and the associated Jacobian is derived. A Jacobian-Free Newton-Krylov (JFNK) method is employed to solve the system, using an approximate Jacobian coupled with incomplete factorization as a preconditioner. The unpreconditioned JFNK slightly outperforms PI, and preconditioned JFNK outperforms both PI and Steffensen-accelerated PI significantly. (author)
A self-consistent nodal method in response matrix formalism for the multigroup diffusion equations
International Nuclear Information System (INIS)
Malambu, E.M.; Mund, E.H.
1996-01-01
We develop a nodal method for the multigroup diffusion equations, based on the transverse integration procedure (TIP). The efficiency of the method rests upon the convergence properties of a high-order multidimensional nodal expansion and upon numerical implementation aspects. The discrete 1D equations are cast in response matrix formalism. The derivation of the transverse leakage moments is self-consistent i.e. does not require additional assumptions. An outstanding feature of the method lies in the linear spatial shape of the local transverse leakage for the first-order scheme. The method is described in the two-dimensional case. The method is validated on some classical benchmark problems. (author)
MUSIC-type imaging of a thin penetrable inclusion from its multi-static response matrix
Park, Won-Kwang; Lesselier, Dominique
2009-07-01
The imaging of a thin inclusion, with dielectric and/or magnetic contrasts with respect to the embedding homogeneous medium, is investigated. A MUSIC-type algorithm operating at a single time-harmonic frequency is developed in order to map the inclusion (that is, to retrieve its supporting curve) from scattered field data collected within the multi-static response matrix. Numerical experiments carried out for several types of inclusions (dielectric and/or magnetic ones, straight or curved ones), mostly single inclusions and also two of them close by as a straightforward extension, illustrate the pros and cons of the proposed imaging method.
International Nuclear Information System (INIS)
Yoriyaz, H.
1986-01-01
In this work a spatial burnup scheme and feedback effects has been implemented into the FERM ( 'Finite Element Response Matrix' )program. The spatially dependent neutronic parameters have been considered in three levels: zonewise calculation, assembly wise calculation and pointwise calculation. Flux and power distributions and the multiplication factor were calculated and compared with the results obtained by CITATIOn program. These comparisons showed that processing time in the Ferm code has been hundred of times shorter and no significant difference has been observed in the assembly average power distribution. (Author) [pt
Energy Technology Data Exchange (ETDEWEB)
Prabhu, Roshan S., E-mail: rprabhu@emory.edu [Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Kandula, Shravan; Liebman, Lang [Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia (United States); Wojno, Ted H.; Hayek, Brent [Division of Oculoplastics, Orbital and Cosmetic Surgery, Emory University, Atlanta, Georgia (United States); Hall, William A.; Shu, Hui-Kuo; Crocker, Ian [Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia (United States)
2013-03-01
Purpose: To retrospectively evaluate institutional outcomes for patients treated with modern radiation therapy (RT) for biopsied orbital pseudotumor (OP). Methods and Materials: Twenty patients (26 affected orbits) with OP were treated with RT between January 2002 and December 2011. All patients underwent biopsy with histopathologic exclusion of other disease processes. Sixteen patients (80%) were treated with intensity modulated RT, 3 (15%) with opposed lateral beams, and 1 (5%) with electrons. Median RT dose was 27 Gy (range 25.2-30.6 Gy). Response to RT was evaluated at 4 months post-RT. Partial response (PR) was defined as improvement in orbital symptoms without an increase in steroid dose. Complete response (CR) 1 and CR 2 were defined as complete resolution of orbital symptoms with reduction in steroid dose (CR 1) or complete tapering of steroids (CR 2). The median follow-up period was 18.6 months (range 4-81.6 months). Results: Seventeen patients (85%) demonstrated response to RT, with 7 (35%), 1 (5%), and 9 (45%) achieving a PR, CR 1, and CR 2, respectively. Of the 17 patients who had ≥PR at 4 months post-RT, 6 (35%) experienced recurrence of symptoms. Age (>46 years vs ≤46 years, P=.04) and clinical response to RT (CR 2 vs CR 1/PR, P=.05) were significantly associated with pseudotumor recurrence. Long-term complications were seen in 7 patients (35%), including 4 with cataract formation, 1 with chronic dry eye, 1 with enophthalmos, and 1 with keratopathy. Conclusions: RT is an effective treatment for improving symptoms and tapering steroids in patients with a biopsy supported diagnosis of OP. Older age and complete response to RT were associated with a significantly reduced probability of symptom recurrence. The observed late complications may be related to RT, chronic use of steroids/immunosuppressants, medical comorbidities, or combination of factors.
International Nuclear Information System (INIS)
Prabhu, Roshan S.; Kandula, Shravan; Liebman, Lang; Wojno, Ted H.; Hayek, Brent; Hall, William A.; Shu, Hui-Kuo; Crocker, Ian
2013-01-01
Purpose: To retrospectively evaluate institutional outcomes for patients treated with modern radiation therapy (RT) for biopsied orbital pseudotumor (OP). Methods and Materials: Twenty patients (26 affected orbits) with OP were treated with RT between January 2002 and December 2011. All patients underwent biopsy with histopathologic exclusion of other disease processes. Sixteen patients (80%) were treated with intensity modulated RT, 3 (15%) with opposed lateral beams, and 1 (5%) with electrons. Median RT dose was 27 Gy (range 25.2-30.6 Gy). Response to RT was evaluated at 4 months post-RT. Partial response (PR) was defined as improvement in orbital symptoms without an increase in steroid dose. Complete response (CR) 1 and CR 2 were defined as complete resolution of orbital symptoms with reduction in steroid dose (CR 1) or complete tapering of steroids (CR 2). The median follow-up period was 18.6 months (range 4-81.6 months). Results: Seventeen patients (85%) demonstrated response to RT, with 7 (35%), 1 (5%), and 9 (45%) achieving a PR, CR 1, and CR 2, respectively. Of the 17 patients who had ≥PR at 4 months post-RT, 6 (35%) experienced recurrence of symptoms. Age (>46 years vs ≤46 years, P=.04) and clinical response to RT (CR 2 vs CR 1/PR, P=.05) were significantly associated with pseudotumor recurrence. Long-term complications were seen in 7 patients (35%), including 4 with cataract formation, 1 with chronic dry eye, 1 with enophthalmos, and 1 with keratopathy. Conclusions: RT is an effective treatment for improving symptoms and tapering steroids in patients with a biopsy supported diagnosis of OP. Older age and complete response to RT were associated with a significantly reduced probability of symptom recurrence. The observed late complications may be related to RT, chronic use of steroids/immunosuppressants, medical comorbidities, or combination of factors
Directory of Open Access Journals (Sweden)
O. Zhuromskyy
2011-09-01
Full Text Available The optical response of a particle composed of a dielectric core surrounded by a densely packed shell of small metal spheres is simulated with the superposition Tmatrix method for realistic material parameters. In order to compute the electric and magnetic particle polarizabilities a single expansion T-matrix is derived from a particle centered T-matrix. Finally the permeability of a medium comprising such particles is found to deviate considerable from unity resulting in a noticeable optical response.
Liu, Tao; Lyu, Mindong; Wang, Zixi; Yan, Shaoze
2018-02-01
Identification of orbit responses can make the active protection operation more easily realize for active magnetic bearings (AMB) in case of touchdowns. This paper presents an identification method of the orbit responses rooting on signal processing of rotor displacements during touchdowns. The recognition method consists of two major steps. Firstly, the combined rub and bouncing is distinguished from the other orbit responses by the mathematical expectation of axis displacements of the rotor. Because when the combined rub and bouncing occurs, the rotor of AMB will not be always close to the touchdown bearings (TDB). Secondly, we recognize the pendulum vibration and the full rub by the Fourier spectrum of displacement in horizontal direction, as the frequency characteristics of the two responses are different. The principle of the whole identification algorithm is illustrated by two sets of signal generated by a dynamic model of the specific rotor-TDB system. The universality of the method is validated by other four sets of signal. Besides, the adaptability of noise is also tested by adding white noises with different strengths, and the result is promising. As the mathematical expectation and Discrete Fourier transform are major calculations of the algorithm, the calculation quantity of the algorithm is low, so it is fast, easily realized and embedded in the AMB controller, which has an important engineering value for the protection of AMBs during touchdowns.
Chen, Hongda; Xiong, Xiaoxiong; Angal, Amit; Geng, Xu; Wu, Aisheng
2016-01-01
The moderate resolution imaging spectroradiometer (MODIS) has 20 reflective solar bands (RSB), covering a spectral range from 0.41 to 2.2 microns, which are calibrated on-orbit using its onboard calibrators, which include a solar diffuser, a solar diffuser stability monitor, and a spectroradiometric calibration assembly. A space view (SV) port is used to provide a background reference and also facilitates near-monthly lunar observations through a spacecraft roll. In every scan, the Earth's surface, SV, and onboard calibrators are viewed via a two-sided scan mirror, the reflectance of which depends on the angle of incidence (AOI) as well as the wavelength of the incident light. Response-versus-scan-angle (RVS) is defined as a dependence function of the scan mirror's reflectance over AOI. An initial RVS for each RSB was measured prelaunch for both Terra and Aqua MODIS. Algorithms have been developed to track the on-orbit RVS variation using the measurements from the onboard calibrators, supplemented with the earth view (EV) trends from pseudoinvariant desert targets obtained at different AOI. Since the mission beginning, the MODIS characterization support team (MCST) has dedicated efforts in evaluating approaches of characterizing the on-orbit RVS. A majority of the approaches focused on fitting the data at each AOI over time and then deriving the relative change at different AOI. The current version of the on-orbit RVS algorithm, as implemented in the collection 6 (C6) level-1B (L1B), is also based on the above rationale. It utilizes the EV response trends from the pseudoinvariant Libyan desert targets to supplement the gain derived from the onboard calibrators. The primary limitation of this approach is the assumption of the temporal stability of these desert sites. Consequently, MCST developed an approach that derives the on-orbit RVS change using measurements from a single desert site, combined with the on-orbit lunar measurements. In addition, the EV and onboard
New computational method for non-LTE, the linear response matrix
International Nuclear Information System (INIS)
Fournier, K.B.; Grasiani, F.R.; Harte, J.A.; Libby, S.B.; More, R.M.; Zimmerman, G.B.
1998-01-01
My coauthors have done extensive theoretical and computational calculations that lay the ground work for a linear response matrix method to calculate non-LTE (local thermodynamic equilibrium) opacities. I will give briefly review some of their work and list references. Then I will describe what has been done to utilize this theory to create a computational package to rapidly calculate mild non-LTE emission and absorption opacities suitable for use in hydrodynamic calculations. The opacities are obtained by performing table look-ups on data that has been generated with a non-LTE package. This scheme is currently under development. We can see that it offers a significant computational speed advantage. It is suitable for mild non-LTE, quasi-steady conditions. And it offers a new insertion path for high-quality non-LTE data. Currently, the linear response matrix data file is created using XSN. These data files could be generated by more detailed and rigorous calculations without changing any part of the implementation in the hydro code. The scheme is running in Lasnex and is being tested and developed
International Nuclear Information System (INIS)
Bedogni, R.; Esposito, A.; Gomez-Ros, J.M.
2010-01-01
Accelerator-based neutron beams are becoming popular tools for material testing, radiation hardness and soft errors studies. The characterization of these beams in terms of dosimetric and spectrometric quantities is a challenging task, mainly due to their wide energy interval (from thermal up to hundreds MeV) and, in certain facilities like VESUVIO - ISIS (RAL, UK), to their small dimension (few cm in radius). Extended Range Bonner Sphere Spectrometers (ERBSS) would be a valuable tool, due to their wide energy range, good photon discrimination and possibility to choose among different central detectors according to the intensity, photon component and time structure of the field. Nevertheless, the non-uniform irradiation of the spheres could lead to important systematic errors. With the aim of bringing the advantages of ERBSS into the characterization of collimated beams, a dedicated study was performed using the VESUVIO spallation-based collimated beam at ISIS (Rutherford Appleton Laboratory, Oxford). Here a 3.21 cm radius collimated beam was characterized using a Dysprosium activation foil-based ERBSS whose response matrix was recalculated for this specific beam diameter. Besides the results of the experimental campaign, this paper presents the calculation of the response matrix and its dependence on the beam dimension.
Nomikou, N; Feichtinger, G A; Saha, S; Nuernberger, S; Heimel, P; Redl, H; McHale, A P
2018-01-01
Gene-activated matrix (GAM)-based therapeutics for tissue regeneration are limited by efficacy, the lack of spatiotemporal control and availability of target cells, all of which impact negatively on their translation to the clinic. Here, an advanced ultrasound-responsive GAM is described containing target cells that facilitates matrix-assisted sonoporation (MAS) to induce osteogenic differentiation. Ultrasound-responsive GAMs consisting of fibrin/collagen hybrid-matrices containing microbubbles, bone morphogenetic protein BMP2/7 coexpression plasmids together with C2C12 cells were treated with ultrasound either in vitro or following parenteral intramuscular implantation in vivo. Using direct measurement for alkaline phosphatase activity, von Kossa staining and immunohistochemical analysis for osteocalcin expression, MAS-stimulated osteogenic differentiation was confirmed in the GAMs in vitro 7 days after treatment with ultrasound. At day 30 post-treatment with ultrasound, ectopic osteogenic differentiation was confirmed in vivo using X-ray microcomputed tomography and histological analysis. Osteogenic differentiation was indicated by the presence of ectopic bone structures in all animals treated with MAS. In addition, bone volumes in this group were statistically greater than those in the control groups. This novel approach of incorporating a MAS capability into GAMs could be exploited to facilitate ex vivo gene transfer with subsequent surgical implantation or alternatively provide a minimally invasive means of stimulating in situ transgene delivery for osteoinductive gene-based therapies. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Response matrix method for neutron transport in reactor lattices using group symmetry properties
International Nuclear Information System (INIS)
Mund, E.H.
1991-01-01
This paper describes a response matrix method for the approximate solution of one-velocity, multi-dimensional transport problems in reactor lattices, with isotropic neutron scattering. The transport equation is solved on a homogeneous cell by using a Petrov-Galerkin technique based on a set of trial and test functions (including polynomials and exponential functions) closely related to transport problems in infinite media. The number of non-zero elements of the response matrices reduces to a minimum when the symmetry properties of the cell are included ab initio in the span of the basis functions. To include these properties, use is made of projection operations which are performed very efficiently on symbolic manipulation programs. Numerical results of model problems in square geometry show a good agreement with reference solutions
Decomposition of continuum {gamma}-ray spectra using synthesized response matrix
Energy Technology Data Exchange (ETDEWEB)
Jandel, M.; Morhac, M.; Kliman, J.; Krupa, L.; Matousek, V. E-mail: vladislav.matousek@savba.sk; Hamilton, J.H.; Ramayya, A.V
2004-01-01
The efficient methods of decomposition of {gamma}-ray spectra, based on the Gold algorithm, are presented. They use a response matrix of Gammasphere, which was obtained by synthesis of simulated and interpolated response functions using a new developed interpolation algorithm. The decomposition method has been applied to the measured spectra of {sup 152}Eu and {sup 56}Co. The results show a very effective removal of the background counts and their concentration into the corresponding photopeaks. The peak-to-total ratio in the spectra achieved after applying the decomposition method is in the interval 0.95-0.99. In addition, a new advanced algorithm of the 'boosted' decomposition has been proposed. In the spectra obtained after applying the boosted decomposition to the measured spectra, very narrow photopeaks are observed with the counts concentrated to several channels.
Wang, Wei; Gao, Xuejiao; Guo, Mengyao; Zhang, Wenlong; Song, Xiaojing; Wang, Tiancheng; Zhang, Zecai; Jiang, Haichao; Cao, Yongguo; Zhang, Naisheng
2014-10-01
Leptospira interrogans (L. interrogans), a worldwide zoonosis, infect humans and animals. In dogs, four syndromes caused by leptospirosis have been identified: icteric, hemorrhagic, uremic (Stuttgart disease) and reproductive (abortion and premature or weak pups), and also it caused inflammation. Extracellular matrix (ECM) is a complex mixture of matrix molecules that is crucial to the reproduction. Both inflammatory response and ECM are closed relative to reproductive. The aim of this study was to clarify how L. interrogans affected the uterus of dogs, by focusing on the inflammatory responses, and ECM expression in dogs uterine tissue infected by L. interrogans. In the present study, 27 dogs were divided into 3 groups, intrauterine infusion with L. interrogans, to make uterine infection, sterile EMJH, and normal saline as a control, respectively. The uteruses were removed by surgical operation in 10, 20, and 30 days, respectively. The methods of histopathological analysis, ELISA, Western blot and qPCR were used. The results showed that L. interrogans induced significantly inflammatory responses, which were characterized by inflammatory cellular infiltration and high expression levels of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in uterine tissue of these dogs. Furthermore, L. interrogans strongly down-regulated the expression of ECM (collagens (CL) IV, fibronectins (FN) and laminins (LN)) in mRNA and protein levels. These data indicated that strongly inflammatory responses, and abnormal regulation of ECM might contribute to the proliferation of dogs infected by L. interrogans. Copyright © 2014 Elsevier Ltd. All rights reserved.
Response matrix of regular moderator volumes with 3He detector using Monte Carlo methods
International Nuclear Information System (INIS)
Baltazar R, A.; Vega C, H. R.; Ortiz R, J. M.; Solis S, L. O.; Castaneda M, R.; Soto B, T. G.; Medina C, D.
2017-10-01
In the last three decades the uses of Monte Carlo methods, for the estimation of physical phenomena associated with the interaction of radiation with matter, have increased considerably. The reason is due to the increase in computing capabilities and the reduction of computer prices. Monte Carlo methods allow modeling and simulating real systems before their construction, saving time and costs. The interaction mechanisms between neutrons and matter are diverse and range from elastic dispersion to nuclear fission; to facilitate the neutrons detection, is necessary to moderate them until reaching electronic equilibrium with the medium at standard conditions of pressure and temperature, in this state the total cross section of the 3 He is large. The objective of the present work was to estimate the response matrix of a proportional detector of 3 He using regular volumes of moderator through Monte Carlo methods. Neutron monoenergetic sources with energies of 10 -9 to 20 MeV and polyethylene moderators of different sizes were used. The calculations were made with the MCNP5 code; the number of stories for each detector-moderator combination was large enough to obtain errors less than 1.5%. We found that for small moderators the highest response is obtained for lower energy neutrons, when increasing the moderator dimension we observe that the response decreases for neutrons of lower energy and increases for higher energy neutrons. The total sum of the responses of each moderator allows obtaining a response close to a constant function. (Author)
Lyu, Mindong; Liu, Tao; Wang, Zixi; Yan, Shaoze; Jia, Xiaohong; Wang, Yuming
2018-05-01
Touchdown can make active magnetic bearings (AMB) unable to work, and bring severe damages to touchdown bearings (TDB). To resolve it, we presents a novel re-levitation method consisting of two operations, i.e., orbit response recognition and rotor re-levitation. In the operation of orbit response recognition, the three orbit responses (pendulum vibration, combined rub and bouncing, and full rub) can be identified by the expectation of radial displacement of rotor and expectation of instantaneous frequency (IF) of rotor motion in the sampling period. In the rotor re-levitation operation, a decentralized PID control algorithm is employed for pendulum vibration and combined rub and bouncing, and the decentralized PID control algorithm and another whirl damping algorithm, in which the weighting factor is determined by the whirl frequency, are jointly executed for the full rub. The method has been demonstrated by the simulation results of an AMB model. The results reveal that the method is effective in actively suppressing the whirl motion and promptly re-levitating the rotor. As the PID control algorithm and the simple operations of signal processing are employed, the algorithm has a low computation intensity, which makes it more easily realized in practical applications.
Shock Wave Response of Iron-based In Situ Metallic Glass Matrix Composites.
Khanolkar, Gauri R; Rauls, Michael B; Kelly, James P; Graeve, Olivia A; Hodge, Andrea M; Eliasson, Veronica
2016-03-02
The response of amorphous steels to shock wave compression has been explored for the first time. Further, the effect of partial devitrification on the shock response of bulk metallic glasses is examined by conducting experiments on two iron-based in situ metallic glass matrix composites, containing varying amounts of crystalline precipitates, both with initial composition Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4. The samples, designated SAM2X5-600 and SAM2X5-630, are X-ray amorphous and partially crystalline, respectively, due to differences in sintering parameters during sample preparation. Shock response is determined by making velocity measurements using interferometry techniques at the rear free surface of the samples, which have been subjected to impact from a high-velocity projectile launched from a powder gun. Experiments have yielded results indicating a Hugoniot Elastic Limit (HEL) to be 8.58 ± 0.53 GPa for SAM2X5-600 and 11.76 ± 1.26 GPa for SAM2X5-630. The latter HEL result is higher than elastic limits for any BMG reported in the literature thus far. SAM2X5-600 catastrophically loses post-yield strength whereas SAM2X5-630, while showing some strain-softening, retains strength beyond the HEL. The presence of crystallinity within the amorphous matrix is thus seen to significantly aid in strengthening the material as well as preserving material strength beyond yielding.
The human metapneumovirus matrix protein stimulates the inflammatory immune response in vitro.
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Audrey Bagnaud-Baule
Full Text Available Each year, during winter months, human Metapneumovirus (hMPV is associated with epidemics of bronchiolitis resulting in the hospitalization of many infants. Bronchiolitis is an acute illness of the lower respiratory tract with a consequent inflammation of the bronchioles. The rapid onset of inflammation suggests the innate immune response may have a role to play in the pathogenesis of this hMPV infection. Since, the matrix protein is one of the most abundant proteins in the Paramyxoviridae family virion, we hypothesized that the inflammatory modulation observed in hMPV infected patients may be partly associated with the matrix protein (M-hMPV response. By western blot analysis, we detected a soluble form of M-hMPV released from hMPV infected cell as well as from M-hMPV transfected HEK 293T cells suggesting that M-hMPV may be directly in contact with antigen presenting cells (APCs during the course of infection. Moreover, flow cytometry and confocal microscopy allowed determining that M-hMPV was taken up by dendritic cells (moDCs and macrophages inducing their activation. Furthermore, these moDCs enter into a maturation process inducing the secretion of a broad range of inflammatory cytokines when exposed to M-hMPV. Additionally, M-hMPV activated DCs were shown to stimulate IL-2 and IFN-γ production by allogeneic T lymphocytes. This M-hMPV-mediated activation and antigen presentation of APCs may in part explain the marked inflammatory immune response observed in pathology induced by hMPV in patients.
Müller, Stephan A; van der Smissen, Anja; von Feilitzsch, Margarete; Anderegg, Ulf; Kalkhof, Stefan; von Bergen, Martin
2012-12-01
Fibroblasts are the main matrix producing cells of the dermis and are also strongly regulated by their matrix environment which can be used to improve and guide skin wound healing processes. Here, we systematically investigated the molecular effects on primary dermal fibroblasts in response to high-sulfated hyaluronan [HA] (hsHA) by quantitative proteomics. The comparison of non- and high-sulfated HA revealed regulation of 84 of more than 1,200 quantified proteins. Based on gene enrichment we found that sulfation of HA alters extracellular matrix remodeling. The collagen degrading enzymes cathepsin K, matrix metalloproteinases-2 and -14 were found to be down-regulated on hsHA. Additionally protein expression of thrombospondin-1, decorin, collagen types I and XII were reduced, whereas the expression of trophoblast glycoprotein and collagen type VI were slightly increased. This study demonstrates that global proteomics provides a valuable tool for revealing proteins involved in molecular effects of growth substrates for further material optimization.
International Nuclear Information System (INIS)
Ding, M.
2004-10-01
The three-spectrometer facility at the Mainz microtron MAMI was supplemented by an additional spectrometer, which is characterized by its short path-length and therefore is called Short Orbit Spectrometer (SOS). At nominal distance from target to SOS (66 cm) the particles to be detected cover a mean path-length between reaction point and detector of 165 cm. Thus for pion electroproduction close to threshold in comparison to the big spectrometers the surviving probability of charged pions with momentum 100 MeV/c raises from 15% to 73%. Consequently the systematic error (''myon contamination''), as for the proposed measurement of the weak form-factors G A (Q 2 ) and G P (Q 2 ), reduces significantly. The main subject of this thesis is the drift chamber for the SOS. Its small relative thickness (0.03% X 0 ), reducing multiple scattering, is optimized with regard to detecting low-energy pions. Due to the innovative character of the driftchamber geometry a dedicated software for track-reconstruction, efficiency-determination etc. had to be developed. A comfortable feature for calibrating the drift path-drift time-relation, represented by cubic splines, was implemented. The resolution of the track detector in the dispersive plane is 76 μaem for the spatial and 0.23 for the angular coordinate (most probable error) and, correspondingly, 110 μm and 0.29 in the non-dispersive plane. For backtracing the reaction quantities from the detector coordinates the inverse transfer-matrix of the spectrometer was determined. For this purpose electrons were scattered quasi-elastically from protons inside the 12 C-nucleus, thus defining the starting angles of the electrons by holes of a sieve collimator. The resulting experimental values for the angular resolution at the target amount to σ φ =1.3 mrad and σ θ =10.6 mrad resp. The momentum calibration of the SOS only can be achieved by quasi-elastic scattering (two-arm experiment). For this reason the contribution of the proton
The response matrix discrete ordinates solution to the 1D radiative transfer equation
International Nuclear Information System (INIS)
Ganapol, Barry D.
2015-01-01
The discrete ordinates method (DOM) of solution to the 1D radiative transfer equation has been an effective method of solution for nearly 70 years. During that time, the method has experienced numerous improvements as numerical and computational techniques have become more powerful and efficient. Here, we again consider the analytical solution to the discrete radiative transfer equation in a homogeneous medium by proposing a new, and consistent, form of solution that improves upon previous forms. Aided by a Wynn-epsilon convergence acceleration, its numerical evaluation can achieve extreme precision as demonstrated by comparison with published benchmarks. Finally, we readily extend the solution to a heterogeneous medium through the star product formulation producing a novel benchmark for closed form Henyey–Greenstein scattering as an example. - Highlights: • Presents a new solution to the RTE called the response matrix DOM (RM/DOM). • Solution representations avoid the instability common in exponential solutions. • Explicit form in terms of matrix hyperbolic functions. • Extreme accuracy through Wynn-epsilon acceleration checked by published benchmarks. • Provides a more transparent numerical evaluation than found previously
Goldberg, Robert K.; Bonacuse, Peter J.; Mital, Subodh K.
2012-01-01
To develop methods for quantifying the effects of the microstructural variations of woven ceramic matrix composites on the effective properties and response of the material, a research program has been undertaken which is described in this paper. In order to characterize and quantify the variations in the microstructure of a five harness satin weave, CVI SiC/SiC, composite material, specimens were serially sectioned and polished to capture images that detailed the fiber tows, matrix, and porosity. Open source quantitative image analysis tools were then used to isolate the constituents and collect relevant statistics such as within ply tow spacing. This information was then used to build two dimensional finite element models that approximated the observed section geometry. With the aid of geometrical models generated by the microstructural characterization process, finite element models were generated and analyses were performed to quantify the effects of the microstructure and its variation on the effective stiffness and areas of stress concentration of the material. The results indicated that the geometry and distribution of the porosity appear to have significant effects on the through-thickness modulus. Similarly, stress concentrations on the outer surface of the composite appear to correlate to regions where the transverse tows are separated by a critical amount.
Role of the Co-based microwires/polymer matrix interface on giant magneto impedance response
International Nuclear Information System (INIS)
Estévez, Diana; Li, Jiawei; Liu, Gang; Man, Qikui; Chang, Chuntao; Wang, Xinmin; Li, Run-Wei
2015-01-01
Highlights: • Co-based microwires-epoxy interface was modified with silane and GMI was evaluated. • XPS confirmed the adhesion of silane onto the wires by Si–O–Si and Fe–O–Si bonds. • GMI curves for treated samples exhibited two-peak behavior and higher GMI ratio. • GMI variation was explained by the change of the surface magnetic anisotropy. • GMI could potentially be used as a surface scanning technique. - Abstract: The interface of Co-based microwires-epoxy composites was modified by applying silane treatment on the surface of the wires and their magneto impedance (MI) response was evaluated. The aim of the surface treatment was to modify the residual stresses that coexist at the microwires/polymer matrix interface and hence the magnetic anisotropy. X-ray Photoelectron Spectroscopy confirmed the covalent attachment of silane molecule onto the wires surface by the presence of Si–O–Si and Fe–O–Si. The MI curve changed from single peak for untreated samples to double peak behavior for treated samples with a significant improvement of MI ratio. Additionally, the magnitude of the anisotropy field increased with the frequency, which may imply a strongly non-uniform stress distribution towards the surface. The MI variation was explained by the change of the surface magnetic anisotropy owing to the modification of the microwires/polymer matrix interface
Applying the response matrix method for solving coupled neutron diffusion and transport problems
International Nuclear Information System (INIS)
Sibiya, G.S.
1980-01-01
The numerical determination of the flux and power distribution in the design of large power reactors is quite a time-consuming procedure if the space under consideration is to be subdivided into very fine weshes. Many computing methods applied in reactor physics (such as the finite-difference method) require considerable computing time. In this thesis it is shown that the response matrix method can be successfully used as an alternative approach to solving the two-dimension diffusion equation. Furthermore it is shown that sufficient accuracy of the method is achieved by assuming a linear space dependence of the neutron currents on the boundaries of the geometries defined for the given space. (orig.) [de
Price elasticity matrix of demand in power system considering demand response programs
Qu, Xinyao; Hui, Hongxun; Yang, Shengchun; Li, Yaping; Ding, Yi
2018-02-01
The increasing renewable energy power generations have brought more intermittency and volatility to the electric power system. Demand-side resources can improve the consumption of renewable energy by demand response (DR), which becomes one of the important means to improve the reliability of power system. In price-based DR, the sensitivity analysis of customer’s power demand to the changing electricity prices is pivotal for setting reasonable prices and forecasting loads of power system. This paper studies the price elasticity matrix of demand (PEMD). An improved PEMD model is proposed based on elasticity effect weight, which can unify the rigid loads and flexible loads. Moreover, the structure of PEMD, which is decided by price policies and load types, and the calculation method of PEMD are also proposed. Several cases are studied to prove the effectiveness of this method.
SynergyFinder: a web application for analyzing drug combination dose-response matrix data.
Ianevski, Aleksandr; He, Liye; Aittokallio, Tero; Tang, Jing
2017-08-01
Rational design of drug combinations has become a promising strategy to tackle the drug sensitivity and resistance problem in cancer treatment. To systematically evaluate the pre-clinical significance of pairwise drug combinations, functional screening assays that probe combination effects in a dose-response matrix assay are commonly used. To facilitate the analysis of such drug combination experiments, we implemented a web application that uses key functions of R-package SynergyFinder, and provides not only the flexibility of using multiple synergy scoring models, but also a user-friendly interface for visualizing the drug combination landscapes in an interactive manner. The SynergyFinder web application is freely accessible at https://synergyfinder.fimm.fi ; The R-package and its source-code are freely available at http://bioconductor.org/packages/release/bioc/html/synergyfinder.html . jing.tang@helsinki.fi. © The Author(s) 2017. Published by Oxford University Press.
A study on measurement on artificial radiation dose rate using the response matrix method
International Nuclear Information System (INIS)
Kidachi, Hiroshi; Ishikawa, Yoichi; Konno, Tatsuya
2004-01-01
We examined accuracy and stability of estimated artificial dose contribution which is distinguished from natural background gamma-ray dose rate using Response Matrix method. Irradiation experiments using artificial gamma-ray sources indicated that there was a linear relationship between observed dose rate and estimated artificial dose contribution, when irradiated artificial gamma-ray dose rate was higher than about 2 nGy/h. Statistical and time-series analyses of long term data made it clear that estimated artificial contribution showed almost constant values under no artificial influence from the nuclear power plants. However, variations of estimated artificial dose contribution were infrequently observed due to of rainfall, detector maintenance operation and occurrence of calibration error. Some considerations on the factors to these variations were made. (author)
LABAN-PEL: a two-dimensional, multigroup diffusion, high-order response matrix code
International Nuclear Information System (INIS)
Mueller, E.Z.
1991-06-01
The capabilities of LABAN-PEL is described. LABAN-PEL is a modified version of the two-dimensional, high-order response matrix code, LABAN, written by Lindahl. The new version extends the capabilities of the original code with regard to the treatment of neutron migration by including an option to utilize full group-to-group diffusion coefficient matrices. In addition, the code has been converted from single to double precision and the necessary routines added to activate its multigroup capability. The coding has also been converted to standard FORTRAN-77 to enhance the portability of the code. Details regarding the input data requirements and calculational options of LABAN-PEL are provided. 13 refs
Van Eester, Dirk
2005-03-01
A semi-analytical method is proposed to evaluate the dielectric response of a plasma to electromagnetic waves in the ion cyclotron domain of frequencies in a D-shaped but axisymmetric toroidal geometry. The actual drift orbit of the particles is accounted for. The method hinges on subdividing the orbit into elementary segments in which the integrations can be performed analytically or by tabulation, and it relies on the local book-keeping of the relation between the toroidal angular momentum and the poloidal flux function. Depending on which variables are chosen, the method allows computation of elementary building blocks for either the wave or the Fokker-Planck equation, but the accent is mainly on the latter. Two types of tangent resonance are distinguished.
Kohno, M; Fujita, T; Nakamoto, C; Suzuki, Y
2000-01-01
Using the SU sub 6 quark-model baryon-baryon interaction which was recently developed by the Kyoto-Niigata group, we calculate N N, LAMBDA N and SIGMA N G--matrices in ordinary nuclear matter. Following the Scheerbaum's prescription, the strength of the single-particle spin-orbit potential S sub B is quantitatively discussed. The S subLAMBDA becomes small because of the cancellation between spin-orbit and anti-symmetric spin-orbit components. The short-range correlation is found to further reduce S subLAMBDA.
Directory of Open Access Journals (Sweden)
T. D. KUSWORO
2015-09-01
Full Text Available This paper investigates the effect of preparation of polyimide/polyethersulfone (PI/PES blending-zeolite mixed matrix membrane through the manipulation of membrane production variables such as polymer concentration, blending composition and zeolite loading. Combination of central composite design and response surface methodology were applied to determine the main effect and interaction effects of these variables on membrane separation performance. The quadratic models between each response and the independent parameters were developed and the response surface models were tested with analysis of variance (ANOVA. In this study, PI/ (PES–zeolite 4A mixed matrix membranes were casted using dry/wet phase inversion technique. The separation performance of mixed matrix membrane had been tested using pure gases such as CO2 and CH4. The results showed that zeolite loading was the most significant variable that influenced the CO2/CH4 selectivity among three variables and the experimental results were in good agreement with those predicted by the proposed regression models. The gas separation performance of the membrane was relatively higher as compare to polymeric membrane. Therefore, combination of central composite design and response surface methodology can be used to prepare optimal condition for mixed matrix membrane fabrication. The incorporation of 20 wt% zeolite 4A into 25 wt% of PI/PES matrix had resulted in a high separation performance of membrane material.
Getzenberg, R H; Coffey, D S
1990-09-01
The DNA of interphase nuclei have very specific three-dimensional organizations that are different in different cell types, and it is possible that this varying DNA organization is responsible for the tissue specificity of gene expression. The nuclear matrix organizes the three-dimensional structure of the DNA and is believed to be involved in the control of gene expression. This study compares the nuclear structural proteins between two sex accessory tissues in the same animal responding to the same androgen stimulation by the differential expression of major tissue-specific secretory proteins. We demonstrate here that the nuclear matrix is tissue specific in the rat ventral prostate and seminal vesicle, and undergoes characteristic alterations in its protein composition upon androgen withdrawal. Three types of nuclear matrix proteins were observed: 1) nuclear matrix proteins that are different and tissue specific in the rat ventral prostate and seminal vesicle, 2) a set of nuclear matrix proteins that either appear or disappear upon androgen withdrawal, and 3) a set of proteins that are common to both the ventral prostate and seminal vesicle and do not change with the hormonal state of the animal. Since the nuclear matrix is known to bind androgen receptors in a tissue- and steroid-specific manner, we propose that the tissue specificity of the nuclear matrix arranges the DNA in a unique conformation, which may be involved in the specific interaction of transcription factors with DNA sequences, resulting in tissue-specific patterns of secretory protein expression.
Dynamic culture substrate that captures a specific extracellular matrix protein in response to light
International Nuclear Information System (INIS)
Nakanishi, Jun; Nakayama, Hidekazu; Horiike, Yasuhiro; Yamaguchi, Kazuo; Garcia, Andres J
2011-01-01
The development of methods for the off-on switching of immobilization or presentation of cell-adhesive peptides and proteins during cell culture is important because such surfaces are useful for the analysis of the dynamic processes of cell adhesion and migration. This paper describes a chemically functionalized gold substrate that captures a genetically tagged extracellular matrix protein in response to light. The substrate was composed of mixed self-assembled monolayers (SAMs) of three disulfide compounds containing (i) a photocleavable poly(ethylene glycol) (PEG), (ii) nitrilotriacetic acid (NTA) and (iii) hepta(ethylene glycol) (EG 7 ). Although the NTA group has an intrinsic high affinity for oligohistidine tag (His-tag) sequences in its Ni 2+ -ion complex, the interaction was suppressed by the steric hindrance of coexisting PEG on the substrate surface. Upon photoirradiation of the substrate to release the PEG chain from the surface, this interaction became possible and hence the protein was captured at the irradiated regions, while keeping the non-specific adsorption of non-His-tagged proteins blocked by the EG 7 underbrush. In this way, we selectively immobilized a His-tagged fibronectin fragment (FNIII 7-10 ) to the irradiated regions. In contrast, when bovine serum albumin-a major serum protein-was added as a non-His-tagged protein, the surface did not permit its capture, with or without irradiation. In agreement with these results, cells were selectively attached to the irradiated patterns only when a His-tagged FNIII 7-10 was added to the medium. These results indicate that the present method is useful for studying the cellular behavior on the specific extracellular matrix protein in cell-culturing environments.
Directory of Open Access Journals (Sweden)
Oksana Shynlova
2013-04-01
Full Text Available Objectives To analyze the expression of genes involved in extracellular matrix (ECM biogenesis and remodeling in vaginal tissue of women with clinically normal pelvic floor support (defined as controls according to the phase of menstrual cycle and postmenopausal women with and without pelvic organ prolapse (POP. Materials and Methods This study examined the expression of matrix metalloproteinases (MMPs, their tissue inhibitors (TIMPs, and the Lysyl oxidase (LOX family genes in the anterior vaginal wall of Caucasian women by real-time RT-PCR. Initially, mRNA expression was assessed in premenopausal controls in the secretory (group 1, n = 10 vs. proliferative (group 2, n = 8 phase of menstrual cycle. In addition, we compared premenopausal controls in the proliferative phase (group 2 vs. postmenopausal controls (group 3, n = 5. Finally, we analyzed postmenopausal controls (group 3 vs. postmenopausal women with advanced POP (group 4, n = 13. Results According to the phase of menstrual cycle, MMP1 was significantly reduced (p = 0.003, whereas the expression of TIMP1 and LOXL4 was significantly up-regulated during proliferative phase (both p < 0.01 when compared to the secretory phase in premenopausal control women. Regarding menopausal status/ageing, all MMPs were down-regulated, while TIMP3, TIMP4 and LOXL2 were significantly up-regulated in postmenopausal control women when compared to premenopausal controls (p = 0.005, p = 0.01 and p < 0.001, correspondingly. TIMP4 and LOXL2 mRNA levels were significantly decreased in postmenopausal POP patients compared to asymptomatic postmenopausal controls (p < 0.01 for both. Conclusions Our results indicate that ovarian cycle and age-related changes influence the expression of genes encoding proteins responsible for ECM metabolism in human vagina. Moreover, POP is associated with alteration in vaginal ECM components after menopause.
Dynamic culture substrate that captures a specific extracellular matrix protein in response to light
Energy Technology Data Exchange (ETDEWEB)
Nakanishi, Jun; Nakayama, Hidekazu; Horiike, Yasuhiro [World Premier International (WPI) Research Center Initiative, International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science - NIMS (Japan); Yamaguchi, Kazuo [Department of Chemistry, Faculty of Science and Research Institute for Photofunctionalized Materials, Kanagawa University (Japan); Garcia, Andres J, E-mail: NAKANISHI.Jun@nims.go.jp [Institute for Bioengineering and Bioscience, Woodruff School of Mechanical Engineering, Georgia Institute of Technology (United States)
2011-08-15
The development of methods for the off-on switching of immobilization or presentation of cell-adhesive peptides and proteins during cell culture is important because such surfaces are useful for the analysis of the dynamic processes of cell adhesion and migration. This paper describes a chemically functionalized gold substrate that captures a genetically tagged extracellular matrix protein in response to light. The substrate was composed of mixed self-assembled monolayers (SAMs) of three disulfide compounds containing (i) a photocleavable poly(ethylene glycol) (PEG), (ii) nitrilotriacetic acid (NTA) and (iii) hepta(ethylene glycol) (EG{sub 7}). Although the NTA group has an intrinsic high affinity for oligohistidine tag (His-tag) sequences in its Ni{sup 2+}-ion complex, the interaction was suppressed by the steric hindrance of coexisting PEG on the substrate surface. Upon photoirradiation of the substrate to release the PEG chain from the surface, this interaction became possible and hence the protein was captured at the irradiated regions, while keeping the non-specific adsorption of non-His-tagged proteins blocked by the EG{sub 7} underbrush. In this way, we selectively immobilized a His-tagged fibronectin fragment (FNIII{sub 7-10}) to the irradiated regions. In contrast, when bovine serum albumin-a major serum protein-was added as a non-His-tagged protein, the surface did not permit its capture, with or without irradiation. In agreement with these results, cells were selectively attached to the irradiated patterns only when a His-tagged FNIII{sub 7-10} was added to the medium. These results indicate that the present method is useful for studying the cellular behavior on the specific extracellular matrix protein in cell-culturing environments.
Dynamic culture substrate that captures a specific extracellular matrix protein in response to light
Directory of Open Access Journals (Sweden)
Jun Nakanishi, Hidekazu Nakayama, Kazuo Yamaguchi, Andres J Garcia and Yasuhiro Horiike
2011-01-01
Full Text Available The development of methods for the off–on switching of immobilization or presentation of cell-adhesive peptides and proteins during cell culture is important because such surfaces are useful for the analysis of the dynamic processes of cell adhesion and migration. This paper describes a chemically functionalized gold substrate that captures a genetically tagged extracellular matrix protein in response to light. The substrate was composed of mixed self-assembled monolayers (SAMs of three disulfide compounds containing (i a photocleavable poly(ethylene glycol (PEG, (ii nitrilotriacetic acid (NTA and (iii hepta(ethylene glycol (EG7. Although the NTA group has an intrinsic high affinity for oligohistidine tag (His-tag sequences in its Ni2+-ion complex, the interaction was suppressed by the steric hindrance of coexisting PEG on the substrate surface. Upon photoirradiation of the substrate to release the PEG chain from the surface, this interaction became possible and hence the protein was captured at the irradiated regions, while keeping the non-specific adsorption of non-His-tagged proteins blocked by the EG7 underbrush. In this way, we selectively immobilized a His-tagged fibronectin fragment (FNIII7–10 to the irradiated regions. In contrast, when bovine serum albumin—a major serum protein—was added as a non-His-tagged protein, the surface did not permit its capture, with or without irradiation. In agreement with these results, cells were selectively attached to the irradiated patterns only when a His-tagged FNIII7-10 was added to the medium. These results indicate that the present method is useful for studying the cellular behavior on the specific extracellular matrix protein in cell-culturing environments.
In vitro extracellular matrix model to evaluate stroma cell response to transvaginal mesh.
Wu, Ming-Ping; Huang, Kuan-Hui; Long, Cheng-Yu; Yang, Chau-Chen; Tong, Yat-Ching
2014-04-01
The use of surgical mesh for female pelvic floor reconstruction has increased in recent years. However, there is paucity of information about the biological responses of host stroma cells to different meshes. This study was aimed to establish an in vitro experimental model to study the micro-environment of extracellular matrix (ECM) with embedded mesh and the stroma cell behaviors to different synthetic meshes. Matrigel multi-cellular co-culture system with embedded mesh was used to evaluate the interaction of stroma cells and synthetic mesh in a simulated ECM environment. Human umbilical vein endothelial cells (HUVEC) and NIH3T3 fibroblasts were inoculated in the system. The established multi-cellular Matrigel co-culture system was used to detect stroma cell recruitment and tube formation ability for different synthetic meshes. HUVEC and NIH3T3 cells were recruited into the mesh interstices and organized into tube-like structures in type I mesh material from Perigee, Marlex and Prolift 24 hr after cell inoculation. On the contrary, there was little recruitment of HUVEC and NIH3T3 cells into the type III mesh of intra-vaginal sling (IVS). The Matrigel multi-cellular co-culture system with embedded mesh offers a useful in vitro model to study the biological behaviors of stroma cells in response to different types of synthetic meshes. The system can help to select ideal mesh candidates before actual implantation into the human body. © 2013 Wiley Periodicals, Inc.
Vibrio cholerae O1 secretes an extracellular matrix in response to antibody-mediated agglutination.
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Danielle E Baranova
Full Text Available Vibrio cholerae O1 is one of two serogroups responsible for epidemic cholera, a severe watery diarrhea that occurs after the bacterium colonizes the human small intestine and secretes a potent ADP-ribosylating toxin. Immunity to cholera is associated with intestinal anti-lipopolysaccharide (LPS antibodies, which are known to inhibit V. cholerae motility and promote bacterial cell-cell crosslinking and aggregation. Here we report that V. cholerae O1 classical and El Tor biotypes produce an extracellular matrix (ECM when forcibly immobilized and agglutinated by ZAC-3 IgG, an intestinally-derived monoclonal antibody (MAb against the core/lipid A region of LPS. ECM secretion, as demonstrated by crystal violet staining and scanning electron microscopy, occurred within 30 minutes of antibody exposure and peaked by 3 hours. Non-motile mutants of V. cholerae did not secrete ECM following ZAC-3 IgG exposure, even though they were susceptible to agglutination. The ECM was enriched in O-specific polysaccharide (OSP but not Vibrio polysaccharide (VPS. Finally, we demonstrate that ECM production by V. cholerae in response to ZAC-3 IgG was associated with bacterial resistant to a secondary complement-mediated attack. In summary, we propose that V. cholerae O1, upon encountering anti-LPS antibodies in the intestinal lumen, secretes an ECM (or O-antigen capsule possibly as a strategy to shield itself from additional host immune factors and to exit an otherwise inhospitable host environment.
Springborg, Michael; Molayem, Mohammad; Kirtman, Bernard
2017-09-01
A theoretical treatment for the orbital response of an infinite, periodic system to a static, homogeneous, magnetic field is presented. It is assumed that the system of interest has an energy gap separating occupied and unoccupied orbitals and a zero Chern number. In contrast to earlier studies, we do not utilize a perturbation expansion, although we do assume the field is sufficiently weak that the occurrence of Landau levels can be ignored. The theory is developed by analyzing results for large, finite systems and also by comparing with the analogous treatment of an electrostatic field. The resulting many-electron Hamilton operator is forced to be hermitian, but hermiticity is not preserved, in general, for the subsequently derived single-particle operators that determine the electronic orbitals. However, we demonstrate that when focusing on the canonical solutions to the single-particle equations, hermiticity is preserved. The issue of gauge-origin dependence of approximate solutions is addressed. Our approach is compared with several previously proposed treatments, whereby limitations in some of the latter are identified.
Yi, Liang; Shi, Zhengguo; Tan, Liangcheng; Deng, Chenglong
2018-03-01
We conducted a statistical study to characterize the nonlinear response of the East Asian summer monsoon (EASM) to its potential forcing factors over the last 260 ka on orbital timescales. We find that both variation in solar insolation and global ice volume were responsible for the nonlinear forcing of orbital-scale monsoonal variations, accounting for 80% of the total variance. Specifically, EASM records with dominated precession variance exhibit a more sensitive response to changes in solar insolation during intervals of enhanced monsoon strength, but are less sensitive during intervals of reduced monsoon strength. In the case of global ice volume with 100-ka variance, this difference is not one of sensitivity but rather a difference in baseline conditions, such as the relative areas of land and sea which affected the land-sea thermal gradient. We therefore suggest that EASM records with dominated precession variance recorded the signal of a shift in the location of the Inter-tropical Convergence Zone, and the associated changes in the incidence of torrential rainfall; while for proxies with dominated 100-ka variance, it recorded changes in the land-sea thermal gradient via its effects on non-torrential precipitation.
Travis, Taryn E; Ghassemi, Pejhman; Prindeze, Nicholas J; Moffatt, Lauren T; Carney, Bonnie C; Alkhalil, Abdulnaser; Ramella-Roman, Jessica C; Shupp, Jeffrey W
2018-01-01
Objective: Proteins of the matrix metalloproteinases family play a vital role in extracellular matrix maintenance and basic physiological processes in tissue homeostasis. The function and activities of matrix metalloproteinases in response to compression therapies have yet to be defined. Here, a swine model of hypertrophic scar was used to profile the transcription of all known 26 matrix metalloproteinases in scars treated with a precise compression dose. Methods: Full-thickness excisional wounds were created. Wounds underwent healing and scar formation. A subset of scars underwent 2 weeks of compression therapy. Biopsy specimens were preserved, and microarrays, reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry were performed to characterize the transcription and expression of various matrix metalloproteinase family members. Results: Microarray results showed that 13 of the known 26 matrix metalloproteinases were differentially transcribed in wounds relative to the preinjury skin. The predominant upregulation of these matrix metalloproteinases during early wound-healing stages declined gradually in later stages of wound healing. The use of compression therapy reduced this decline in 10 of the 13 differentially regulated matrix metalloproteinases. Further investigation of MMP7 using reverse transcription-polymerase chain reaction confirmed the effect of compression on transcript levels. Assessment of MMP7 at the protein level using Western blotting and immunohistochemistry was concordant. Conclusions: In a swine model of hypertrophic scar, the application of compression to hypertrophic scar attenuated a trend of decreasing levels of matrix metalloproteinases during the process of hypertrophic wound healing, including MMP7, whose enzyme regulation was confirmed at the protein level.
Introducing Earth's Orbital Eccentricity
Oostra, Benjamin
2015-01-01
Most students know that planetary orbits, including Earth's, are elliptical; that is Kepler's first law, and it is found in many science textbooks. But quite a few are mistaken about the details, thinking that the orbit is very eccentric, or that this effect is somehow responsible for the seasons. In fact, the Earth's orbital eccentricity is…
Schuecker, Clara; Davila, Carlos G.; Rose, Cheryl A.
2010-01-01
Five models for matrix damage in fiber reinforced laminates are evaluated for matrix-dominated loading conditions under plane stress and are compared both qualitatively and quantitatively. The emphasis of this study is on a comparison of the response of embedded plies subjected to a homogeneous stress state. Three of the models are specifically designed for modeling the non-linear response due to distributed matrix cracking under homogeneous loading, and also account for non-linear (shear) behavior prior to the onset of cracking. The remaining two models are localized damage models intended for predicting local failure at stress concentrations. The modeling approaches of distributed vs. localized cracking as well as the different formulations of damage initiation and damage progression are compared and discussed.
International Nuclear Information System (INIS)
Mirdamadi, M.; Johnson, W.S.
1993-01-01
Cross-ply laminate behavior of Ti-15V-3Cr-3AI-3Sn (Ti-15-3) matrix reinforced with continuous silicon-carbide fibers (SCS-6) subjected to a generic hypersonic flight profile was evaluated experimentally and analytically. Thermomechanical fatigue test techniques were developed to conduct a simulation of a generic hypersonic flight profile. A micromechanical analysis was used. The analysis predicts the stress-strain response of the laminate and of the constituents in each ply during thermal and mechanical cycling by using only constituent properties as input. The fiber was modeled as elastic with transverse orthotropic and temperature-dependent properties. The matrix was modeled using a thermoviscoplastic constitutive relation. The fiber transverse modulus was reduced in the analysis to simulate the fiber-matrix interface failure. Excellent correlation was found between measured and predicted laminate stress-strain response due to generic hypersonic flight profile when fiber debonding was modeled
Response matrix Monte Carlo based on a general geometry local calculation for electron transport
International Nuclear Information System (INIS)
Ballinger, C.T.; Rathkopf, J.A.; Martin, W.R.
1991-01-01
A Response Matrix Monte Carlo (RMMC) method has been developed for solving electron transport problems. This method was born of the need to have a reliable, computationally efficient transport method for low energy electrons (below a few hundred keV) in all materials. Today, condensed history methods are used which reduce the computation time by modeling the combined effect of many collisions but fail at low energy because of the assumptions required to characterize the electron scattering. Analog Monte Carlo simulations are prohibitively expensive since electrons undergo coulombic scattering with little state change after a collision. The RMMC method attempts to combine the accuracy of an analog Monte Carlo simulation with the speed of the condensed history methods. Like condensed history, the RMMC method uses probability distributions functions (PDFs) to describe the energy and direction of the electron after several collisions. However, unlike the condensed history method the PDFs are based on an analog Monte Carlo simulation over a small region. Condensed history theories require assumptions about the electron scattering to derive the PDFs for direction and energy. Thus the RMMC method samples from PDFs which more accurately represent the electron random walk. Results show good agreement between the RMMC method and analog Monte Carlo. 13 refs., 8 figs
Root maturation and dentin–pulp response to enamel matrix derivative in pulpotomized permanent teeth
Directory of Open Access Journals (Sweden)
Sherif S Darwish
2014-01-01
Full Text Available The success of pulpotomy of young permanent teeth depends on the proper selection of dressing materials. This study aimed to evaluate the histological and histomorphometric response of dentin–pulp complex to the enamel matrix derivative (Emdogain® gel compared to that of calcium hydroxide when used as a pulp dressing in immature young permanent dogs’ teeth. Dentin-like tissues bridging the full width of the coronal pulp at the interface between the injured and healthy pulp tissues were seen after 1 month in both groups. With time, the dentin bridge increased in thickness for calcium hydroxide but disintegrated and fully disappeared for Emdogain-treated group. Progressive inflammation and total pulp degeneration were only evident with Emdogain-treated group. The root apices of Emdogain-treated teeth became matured and closed by cementum that attached to new alveolar bone by a well-oriented periodontal ligament. In young permanent dentition, Emdogain could be a good candidate for periodontium but not dentino–pulpal complex regeneration.
Responsibility and Sustainability in a Food Chain: A Priority Matrix Analysis
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Francesco Caracciolo
2011-12-01
Full Text Available This paper shows the results of empirical research conducted to assess the sustainability of a typical food supply chain, suggesting feasible solutions to satisfy inter-dimensional requisites of durable development. The analysis was conducted with reference to the supply chain of the San Marzano tomato (SMZ, a typical local food. The product is endowed with an origin certification label (PDO, meeting demand within high-value market niches. The SMZ is a flagship product in the Italian region of Campania and has benefited from several regionally funded interventions, such as genetic research and support for the application for EU certification of origin. Two key findings emerged from the research. First, the results allowed us to define a Stakeholder Priority and Responsibilities’ Matrix (SPRM, and monitor the sustainability trend of SMZ food supply chains. Second, the consistency between the adoption of quality strategy (brand of origin and sustainable development of the sector was evaluated. Despite its intrinsic characteristics and its organized, well-defined structure, the SMZ food supply chain is unable to address sustainable objectives without considerable public intervention and support. In terms of sustainability, to be able to show desirable food chain characteristics, the existence of a fully collaborative relationship between the actors has to be ascertained. Identifying shared goals is essential to assign and implement coordinated actions, pooling responsibility for product quality into social and environmental dimensions.
Directory of Open Access Journals (Sweden)
Elizabeth L. Siegler
2016-11-01
Full Text Available Increasing attention has been given to the tumor microenvironment (TME, which includes cellular and structural components such as fibroblasts, immune cells, vasculature, and extracellular matrix (ECM that surround tumor sites. These components contribute to tumor growth and metastasis and are one reason why traditional chemotherapy often is insufficient to eradicate the tumor completely. Newer treatments that target aspects of the TME, such as antiangiogenic and immunostimulatory therapies, have seen limited clinical success despite promising preclinical results. This can be attributed to a number of reasons, including a lack of drug penetration deeper into the necrotic tumor core, nonspecific delivery, rapid clearance from serum, or toxic side effects at high doses. Nanoparticles offer a potential solution to all of these obstacles, and many recent studies have shown encouraging results using nanomedicine to target TME vasculature, ECM, and immune response. While few of these platforms have made it to clinical trials to date, these strategies are relatively new and may offer a way to improve the effects of anticancer therapies.
Unconventional low-field magnetic response of a diffusive ring with spin–orbit coupling
International Nuclear Information System (INIS)
Patra, Moumita; Maiti, Santanu K.
2017-01-01
We report an unconventional behavior of electron transport in the limit of zero magnetic flux in a one-dimensional disordered ring, be it completely random or any correlated one, subjected to Rashba spin–orbit (SO) coupling. It exhibits much higher circulating current compared to a fully perfect ring for a wide range of SO coupling yielding larger electrical conductivity which is clearly verified from our Drude weight analysis. - Highlights: • Unconventional behavior of electron transport in a 1D disordered ring is reported. • Interplay between Rashba So interaction and disorder is discussed. • Disordered ring provides much higher current compared to a perfect one. • Results are independent with disorderness, be it correlated or random. • MI transition and selective switching effects are discussed.
Unconventional low-field magnetic response of a diffusive ring with spin–orbit coupling
Energy Technology Data Exchange (ETDEWEB)
Patra, Moumita; Maiti, Santanu K., E-mail: santanu.maiti@isical.ac.in
2017-01-30
We report an unconventional behavior of electron transport in the limit of zero magnetic flux in a one-dimensional disordered ring, be it completely random or any correlated one, subjected to Rashba spin–orbit (SO) coupling. It exhibits much higher circulating current compared to a fully perfect ring for a wide range of SO coupling yielding larger electrical conductivity which is clearly verified from our Drude weight analysis. - Highlights: • Unconventional behavior of electron transport in a 1D disordered ring is reported. • Interplay between Rashba So interaction and disorder is discussed. • Disordered ring provides much higher current compared to a perfect one. • Results are independent with disorderness, be it correlated or random. • MI transition and selective switching effects are discussed.
Irshad, M.; Scheres, N.; Anssari Moin, D.; Crielaard, W.; Loos, B.G.; Wismeijer, D.; Laine, M.L.
2013-01-01
Background and Objective To assess inflammatory reactions of fibroblasts in the pathophysiology of peri-implantitis, we compared the pro-inflammatory and matrix-degrading responses of gingival and granulation tissue fibroblasts from periodontally healthy controls, peri-implantitis, and periodontitis
DEFF Research Database (Denmark)
Bak, Keld L.; Jørgensen, Poul; Jensen, H.J.A.
1992-01-01
A new scheme for obtaining first-order nonadiabatic coupling matrix elements (FO-NACME) for multiconfigurational self-consistent-field (MCSCF) wave functions is presented. The FO-NACME are evaluated from residues of linear response functions. The residues involve the geometrical response of a ref......A new scheme for obtaining first-order nonadiabatic coupling matrix elements (FO-NACME) for multiconfigurational self-consistent-field (MCSCF) wave functions is presented. The FO-NACME are evaluated from residues of linear response functions. The residues involve the geometrical response...... to the full configuration interaction limit. Comparisons are made with state-averaged MCSCF results for MgH2 and finite-difference configuration interaction by perturbation with multiconfigurational zeroth-order wave function reflected by interactive process (CIPSI) results for BH....
Asmussen, Niels; Lin, Zhao; McClure, Michael J; Schwartz, Zvi; Boyan, Barbara D
2017-12-09
Endochondral bone formation is a precise and highly ordered process whose exact regulatory framework is still being elucidated. Multiple regulatory pathways are known to be involved. In some cases, regulation impacts gene expression, resulting in changes in chondrocyte phenotypic expression and extracellular matrix synthesis. Rapid regulatory mechanisms are also involved, resulting in release of enzymes, factors and micro RNAs stored in extracellular matrisomes called matrix vesicles. Vitamin D metabolites modulate endochondral development via both genomic and rapid membrane-associated signaling pathways. 1α,25-dihydroxyvitamin D3 [1α,25(OH) 2 D 3 ] acts through the vitamin D receptor (VDR) and a membrane associated receptor, protein disulfide isomerase A3 (PDIA3). 24R,25-dihydroxyvitamin D3 [24R,25(OH) 2 D 3 ] affects primarily chondrocytes in the resting zone (RC) of the growth plate, whereas 1α,25(OH) 2 D 3 affects cells in the prehypertrophic and upper hypertrophic cell zones (GC). This includes genomically directing the cells to produce matrix vesicles with zone specific characteristics. In addition, vitamin D metabolites produced by the cells interact directly with the matrix vesicle membrane via rapid signal transduction pathways, modulating their activity in the matrix. The matrix vesicle payload is able to rapidly impact the extracellular matrix via matrix processing enzymes as well as providing a feedback mechanism to the cells themselves via the contained micro RNAs. Copyright © 2017. Published by Elsevier Inc.
Analytical, experimental, and Monte Carlo system response matrix for pinhole SPECT reconstruction
International Nuclear Information System (INIS)
Aguiar, Pablo; Pino, Francisco; Silva-Rodríguez, Jesús; Pavía, Javier; Ros, Doménec; Ruibal, Álvaro
2014-01-01
Purpose: To assess the performance of two approaches to the system response matrix (SRM) calculation in pinhole single photon emission computed tomography (SPECT) reconstruction. Methods: Evaluation was performed using experimental data from a low magnification pinhole SPECT system that consisted of a rotating flat detector with a monolithic scintillator crystal. The SRM was computed following two approaches, which were based on Monte Carlo simulations (MC-SRM) and analytical techniques in combination with an experimental characterization (AE-SRM). The spatial response of the system, obtained by using the two approaches, was compared with experimental data. The effect of the MC-SRM and AE-SRM approaches on the reconstructed image was assessed in terms of image contrast, signal-to-noise ratio, image quality, and spatial resolution. To this end, acquisitions were carried out using a hot cylinder phantom (consisting of five fillable rods with diameters of 5, 4, 3, 2, and 1 mm and a uniform cylindrical chamber) and a custom-made Derenzo phantom, with center-to-center distances between adjacent rods of 1.5, 2.0, and 3.0 mm. Results: Good agreement was found for the spatial response of the system between measured data and results derived from MC-SRM and AE-SRM. Only minor differences for point sources at distances smaller than the radius of rotation and large incidence angles were found. Assessment of the effect on the reconstructed image showed a similar contrast for both approaches, with values higher than 0.9 for rod diameters greater than 1 mm and higher than 0.8 for rod diameter of 1 mm. The comparison in terms of image quality showed that all rods in the different sections of a custom-made Derenzo phantom could be distinguished. The spatial resolution (FWHM) was 0.7 mm at iteration 100 using both approaches. The SNR was lower for reconstructed images using MC-SRM than for those reconstructed using AE-SRM, indicating that AE-SRM deals better with the
International Nuclear Information System (INIS)
Conti, C.F.S.; Watson, F.V.
1991-01-01
A computational code to solve a two energy group neutron diffusion problem has been developed base d on the Response Matrix Method. That method solves the global problem of PWR core, without using the cross sections homogenization process, thus it is equivalent to a pontwise core calculation. The present version of the code calculates the response matrices by the first order perturbative method and considers developments on arbitrary order Fourier series for the boundary fluxes and interior fluxes. (author)
Pápai, Ferenc; Szűcs, István
2015-01-01
The singular value decomposition of the measured frequency response function matrix, as a very effective tool of experimental modal analysis is used over the last twenty-five years. The complex mode indication function has become a common numerical tool in processing experimental data. There are many references on the development of complex mode indication function including the enhanced mode indication function and its use together with the enhanced frequency response function to form spatia...
Pápai, Ferenc; Szűcs, István
2015-01-01
The singular value decomposition of the measured frequency response function matrix, as a very effective tool of experimental modal analysis is used over the last twenty-five years. The complex mode indication function has become a common numerical tool in processing experimental data. There are many references on the development of complex mode indication function including the enhanced mode indication function and its use together with the enhanced frequency response function to form spatia...
Directory of Open Access Journals (Sweden)
Irene Amigo-Jiménez
Full Text Available Matrix metalloproteinase-9 (MMP-9 contributes to chronic lymphocytic leukemia (CLL pathology by regulating cell migration and preventing spontaneous apoptosis. It is not known if MMP-9 is involved in CLL cell response to chemotherapy and we address this in the present study, using arsenic trioxide (ATO and fludarabine as examples of cytotoxic drugs.We used primary cells from the peripheral blood of CLL patients and MEC-1 cells stably transfected with an empty vector or a vector containing MMP-9. The effect of ATO and fludarabine was determined by flow cytometry and by the MTT assay. Expression of mRNA was measured by RT-PCR and qPCR. Secreted and cell-bound MMP-9 was analyzed by gelatin zymography and flow cytometry, respectively. Protein expression was analyzed by Western blotting and immunoprecipitation. Statistical analyses were performed using the two-tailed Student's t-test.In response to ATO or fludarabine, CLL cells transcriptionally upregulated MMP-9, preceding the onset of apoptosis. Upregulated MMP-9 primarily localized to the membrane of early apoptotic cells and blocking apoptosis with Z-VAD prevented MMP-9 upregulation, thus linking MMP-9 to the apoptotic process. Culturing CLL cells on MMP-9 or stromal cells induced drug resistance, which was overcome by anti-MMP-9 antibodies. Accordingly, MMP-9-MEC-1 transfectants showed higher viability upon drug treatment than Mock-MEC-1 cells, and this effect was blocked by silencing MMP-9 with specific siRNAs. Following drug exposure, expression of anti-apoptotic proteins (Mcl-1, Bcl-xL, Bcl-2 and the Mcl-1/Bim, Mcl-1/Noxa, Bcl-2/Bax ratios were higher in MMP-9-cells than in Mock-cells. Similar results were obtained upon culturing primary CLL cells on MMP-9.Our study describes for the first time that MMP-9 induces drug resistance by modulating proteins of the Bcl-2 family and upregulating the corresponding anti-apoptotic/pro-apoptotic ratios. This is a novel role for MMP-9 contributing to CLL
Directory of Open Access Journals (Sweden)
Wunner William
2006-12-01
Full Text Available Abstract Background Matrix protein 2 (M2 is an integral tetrameric membrane protein of influenza A virus (IAV. Its ectodomain (M2e shows remarkably little diversity amongst human IAV strains. As M2e-specific antibodies (Abs have been shown to reduce the severity of infection in animals, M2e is being studied for its capability of providing protection against a broad range of IAV strains. Presently, there is little information about the concentration of M2e-specific Abs in humans. Two previous studies made use of ELISA and Western blot against M2e peptides and recombinant M2 protein as immunosorbents, respectively, and reported Ab titers to be low or undetectable. An important caveat is that these assays may not have detected all Abs capable of binding to native tetrameric M2e. Therefore, we developed an assay likely to detect all M2e tetramer-specific Abs. Results We generated a HeLa cell line that expressed full length tetrameric M2 (HeLa-M2 or empty vector (HeLa-C10 under the control of the tetracycline response element. These cell lines were then used in parallel as immunosorbents in ELISA. The assay was standardized and M2e-specific Ab titers quantified by means of purified murine or chimeric (mouse variable regions, human constant regions M2e-specific Abs in the analysis of mouse and human sera, respectively. We found that the cell-based ELISA was substantially more effective than immobilized M2e peptide in detecting M2e-specific Abs in sera of mice that had recovered from repetitive IAV infections. Still, titers remained low ( Conclusion The results provide convincing evidence that M2e-specific Ab-mediated protection is currently lacking or suboptimal in humans.
Shon, Soo-Min; Jang, Hee Jeong; Schellingerhout, Dawid; Kim, Jeong-Yeon; Ryu, Wi-Sun; Lee, Su-Kyoung; Kim, Jiwon; Park, Jin-Yong; Oh, Ji Hye; Kang, Jeong Wook; Je, Kang-Hoon; Park, Jung E; Kim, Kwangmeyung; Kwon, Ick Chan; Lee, Juneyoung; Nahrendorf, Matthias; Park, Jong-Ho; Kim, Dong-Eog
2017-09-25
The aim of this study is to identify the principal circulating factors that modulate atheromatous matrix metalloproteinase (MMP) activity in response to diet and exercise.Methods and Results:Apolipoprotein-E knock-out (ApoE -/- ) mice (n=56) with pre-existing plaque, fed either a Western diet (WD) or normal diet (ND), underwent either 10 weeks of treadmill exercise or had no treatment. Atheromatous MMP activity was visualized using molecular imaging with a MMP-2/9 activatable near-infrared fluorescent (NIRF) probe. Exercise did not significantly reduce body weight, visceral fat, and plaque size in either WD-fed animals or ND-fed animals. However, atheromatous MMP-activity was different; ND animals that did or did not exercise had similarly low MMP activities, WD animals that did not exercise had high MMP activity, and WD animals that did exercise had reduced levels of MMP activity, close to the levels of ND animals. Factor analysis and path analysis showed that soluble vascular cell adhesion molecule (sVCAM)-1 was directly positively correlated to atheromatous MMP activity. Adiponectin was indirectly negatively related to atheromatous MMP activity by way of sVCAM-1. Resistin was indirectly positively related to atheromatous MMP activity by way of sVCAM-1. Visceral fat amount was indirectly positively associated with atheromatous MMP activity, by way of adiponectin reduction and resistin elevation. MMP-2/9 imaging of additional mice (n=18) supported the diet/exercise-related anti-atherosclerotic roles for sVCAM-1. Diet and exercise affect atheromatous MMP activity by modulating the systemic inflammatory milieu, with sVCAM-1, resistin, and adiponectin closely interacting with each other and with visceral fat.
Jochum, M.; Peacock, S.; Moore, K.; Lindsay, K.
2010-07-01
A global general circulation model coupled to an ocean ecosystem model is used to quantify the response of carbon fluxes and climate to changes in orbital forcing. Compared to the present-day simulation, the simulation with the Earth's orbital parameters from 115,000 years ago features significantly cooler northern high latitudes but only moderately cooler southern high latitudes. This asymmetry is explained by a 30% reduction of the strength of the Atlantic Meridional Overturning Circulation that is caused by an increased Arctic sea ice export and a resulting freshening of the North Atlantic. The strong northern high-latitude cooling and the direct insolation induced tropical warming lead to global shifts in precipitation and winds to the order of 10%-20%. These climate shifts lead to regional differences in air-sea carbon fluxes of the same order. However, the differences in global net air-sea carbon fluxes are small, which is due to several effects, two of which stand out: first, colder sea surface temperature leads to a more effective solubility pump but also to increased sea ice concentration which blocks air-sea exchange, and second, the weakening of Southern Ocean winds that is predicted by some idealized studies occurs only in part of the basin, and is compensated by stronger winds in other parts.
Agar/gelatin bilayer gel matrix fabricated by simple thermo-responsive sol-gel transition method.
Wang, Yifeng; Dong, Meng; Guo, Mengmeng; Wang, Xia; Zhou, Jing; Lei, Jian; Guo, Chuanhang; Qin, Chaoran
2017-08-01
We present a simple and environmentally-friendly method to generate an agar/gelatin bilayer gel matrix for further biomedical applications. In this method, the thermally responsive sol-gel transitions of agar and gelatin combined with the different transition temperatures are exquisitely employed to fabricate the agar/gelatin bilayer gel matrix and achieve separate loading for various materials (e.g., drugs, fluorescent materials, and nanoparticles). Importantly, the resulting bilayer gel matrix provides two different biopolymer environments (a polysaccharide environment vs a protein environment) with a well-defined border, which allows the loaded materials in different layers to retain their original properties (e.g., magnetism and fluorescence) and reduce mutual interference. In addition, the loaded materials in the bilayer gel matrix exhibit an interesting release behavior under the control of thermal stimuli. Consequently, the resulting agar/gelatin bilayer gel matrix is a promising candidate for biomedical applications in drug delivery, controlled release, fluorescence labeling, and bio-imaging. Copyright © 2017 Elsevier B.V. All rights reserved.
Analytical, experimental, and Monte Carlo system response matrix for pinhole SPECT reconstruction
Energy Technology Data Exchange (ETDEWEB)
Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es [Fundación Ramón Domínguez, Medicina Nuclear, CHUS, Spain and Grupo de Imaxe Molecular, IDIS, Santiago de Compostela 15706 (Spain); Pino, Francisco [Unitat de Biofísica, Facultat de Medicina, Universitat de Barcelona, Spain and Servei de Física Médica i Protecció Radiológica, Institut Catalá d' Oncologia, Barcelona 08036 (Spain); Silva-Rodríguez, Jesús [Fundación Ramón Domínguez, Medicina Nuclear, CHUS, Santiago de Compostela 15706 (Spain); Pavía, Javier [Servei de Medicina Nuclear, Hospital Clínic, Barcelona (Spain); Institut d' Investigacions Biomèdiques August Pí i Sunyer (IDIBAPS) (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Ros, Doménec [Unitat de Biofísica, Facultat de Medicina, Casanova 143 (Spain); Institut d' Investigacions Biomèdiques August Pí i Sunyer (IDIBAPS) (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Ruibal, Álvaro [Servicio Medicina Nuclear, CHUS (Spain); Grupo de Imaxe Molecular, Facultade de Medicina (USC), IDIS, Santiago de Compostela 15706 (Spain); Fundación Tejerina, Madrid (Spain); and others
2014-03-15
Purpose: To assess the performance of two approaches to the system response matrix (SRM) calculation in pinhole single photon emission computed tomography (SPECT) reconstruction. Methods: Evaluation was performed using experimental data from a low magnification pinhole SPECT system that consisted of a rotating flat detector with a monolithic scintillator crystal. The SRM was computed following two approaches, which were based on Monte Carlo simulations (MC-SRM) and analytical techniques in combination with an experimental characterization (AE-SRM). The spatial response of the system, obtained by using the two approaches, was compared with experimental data. The effect of the MC-SRM and AE-SRM approaches on the reconstructed image was assessed in terms of image contrast, signal-to-noise ratio, image quality, and spatial resolution. To this end, acquisitions were carried out using a hot cylinder phantom (consisting of five fillable rods with diameters of 5, 4, 3, 2, and 1 mm and a uniform cylindrical chamber) and a custom-made Derenzo phantom, with center-to-center distances between adjacent rods of 1.5, 2.0, and 3.0 mm. Results: Good agreement was found for the spatial response of the system between measured data and results derived from MC-SRM and AE-SRM. Only minor differences for point sources at distances smaller than the radius of rotation and large incidence angles were found. Assessment of the effect on the reconstructed image showed a similar contrast for both approaches, with values higher than 0.9 for rod diameters greater than 1 mm and higher than 0.8 for rod diameter of 1 mm. The comparison in terms of image quality showed that all rods in the different sections of a custom-made Derenzo phantom could be distinguished. The spatial resolution (FWHM) was 0.7 mm at iteration 100 using both approaches. The SNR was lower for reconstructed images using MC-SRM than for those reconstructed using AE-SRM, indicating that AE-SRM deals better with the
Abbott, Rosalyn D; Koptiuch, Cathryn; Iatridis, James C; Howe, Alan K; Badger, Gary J; Langevin, Helene M
2012-01-01
In areolar “loose” connective tissue, fibroblasts remodel their cytoskeleton within minutes in response to static stretch resulting in increased cell body cross-sectional area that relaxes the tissue to a lower state of resting tension. It remains unknown whether the loosely arranged collagen matrix, characteristic of areolar connective tissue, is required for this cytoskeletal response to occur. The purpose of this study was to evaluate cytoskeletal remodeling of fibroblasts in and dissociated from areolar and dense connective tissue in response to 2 hours of static stretch in both native tissue and collagen gels of varying crosslinking. Rheometric testing indicated that the areolar connective tissue had a lower dynamic modulus and was more viscous than the dense connective tissue. In response to stretch, cells within the more compliant areolar connective tissue adopted a large “sheet-like” morphology that was in contrast to the smaller dendritic morphology in the dense connective tissue. By adjusting the in vitro collagen crosslinking, and the resulting dynamic modulus, it was demonstrated that cells dissociated from dense connective tissue are capable of responding when seeded into a compliant matrix, while cells dissociated from areolar connective tissue can lose their ability to respond when their matrix becomes stiffer. This set of experiments indicated stretch-induced fibroblast expansion was dependent on the distinct matrix material properties of areolar connective tissues as opposed to the cells’ tissue of origin. These results also suggest that disease and pathological processes with increased crosslinks, such as diabetes and fibrosis, could impair fibroblast responsiveness in connective tissues. PMID:22552950
Directory of Open Access Journals (Sweden)
Jesper Sjolte
2014-09-01
Full Text Available The relation between δ 18O of precipitation and temperature has been used in numerous studies to reconstruct past temperatures at ice core sites in Greenland and Antarctica. During the past two decades, it has become clear that the slope between δ 18O and temperature varies in both space and time. Here, we use a general circulation model driven by changes in orbital parameters to investigate the Greenland δ 18O–temperature relation for the previous interglacial, the Eemian. In our analysis, we focus on changes in the moisture source regions, and the results underline the importance of taking the seasonality of climate change into account. The orbitally driven experiments show that continental evaporation over North America increases during summer in the warm parts of the Eemian, while marine evaporation decreases. This likely flattens the Greenland δ 18O response to temperature during summer. Since the main climate change in the experiments occurs during summer this adds to a limited response of δ 18O, which is more strongly tied to temperature during winter than during summer. A south–west to north–east gradient in the δ 18O–temperature slope is also evident for Greenland, with low slopes in the south–west and steeper slopes in the north–east. This probably reflects the proportion of continental moisture and Arctic moisture arriving in Greenland, with more continental moisture in the south–west and less in the north–east, and vice versa for the Arctic moisture.
Analytic robust stability analysis of SVD orbit feedback
Pfingstner, Jürgen
2012-01-01
Orbit feedback controllers are indispensable for the operation of modern particle accelerators. Many such controllers are based on the decoupling of the inputs and outputs of the system to be controlled with the help of the singular value decomposition (SVD controller). It is crucial to verify the stability of SVD controllers, also in the presence of mismatches between the used accelerator model and the real machine (robust stability problem). In this paper, analytical criteria for guaranteed stability margins of SVD orbit feedback systems for three different types of model mismatches are presented: scaling errors of actuators and BPMs (beam position monitors) and additive errors of the orbit response matrix. For the derivation of these criteria, techniques from robust control theory have been used, e.g the small gain theorem. The obtained criteria can be easily applied directly to other SVD orbit feedback systems. As an example, the criteria were applied to the orbit feedback system of the Compact Linear ...
Liu, Hung-Yi; Korc, Murray; Lin, Chien-Chi
2018-04-01
The tumor microenvironment (TME) governs all aspects of cancer progression and in vitro 3D cell culture platforms are increasingly developed to emulate the interactions between components of the stromal tissues and cancer cells. However, conventional cell culture platforms are inadequate in recapitulating the TME, which has complex compositions and dynamically changing matrix mechanics. In this study, we developed a dynamic gelatin-hyaluronic acid hybrid hydrogel system through integrating modular thiol-norbornene photopolymerization and enzyme-triggered on-demand matrix stiffening. In particular, gelatin was dually modified with norbornene and 4-hydroxyphenylacetic acid to render this bioactive protein photo-crosslinkable (through thiol-norbornene gelation) and responsive to tyrosinase-triggered on-demand stiffening (through HPA dimerization). In addition to the modified gelatin that provides basic cell adhesive motifs and protease cleavable sequences, hyaluronic acid (HA), an essential tumor matrix, was modularly and covalently incorporated into the cell-laden gel network. We systematically characterized macromer modification, gel crosslinking, as well as enzyme-triggered stiffening and degradation. We also evaluated the influence of matrix composition and dynamic stiffening on pancreatic ductal adenocarcinoma (PDAC) cell fate in 3D. We found that either HA-containing matrix or a dynamically stiffened microenvironment inhibited PDAC cell growth. Interestingly, these two factors synergistically induced cell phenotypic changes that resembled cell migration and/or invasion in 3D. Additional mRNA expression array analyses revealed changes unique to the presence of HA, to a stiffened microenvironment, or to the combination of both. Finally, we presented immunostaining and mRNA expression data to demonstrate that these irregular PDAC cell phenotypes were a result of matrix-induced epithelial-mesenchymal transition (EMT). Copyright © 2018 Elsevier Ltd. All rights
Directory of Open Access Journals (Sweden)
Jianguo Ding
2014-11-01
Full Text Available Portal frame structures are widely used in industrial building design but unfortunately are often damaged during an earthquake. As a result, a study on the seismic response of this type of structure is important to both human safety and future building designs. Traditionally, finite element methods such as the ANSYS and MIDAS have been used as the primary methods of computing the response of such a structure during an earthquake; however, these methods yield low calculation efficiencies. In this paper, the mechanical model of a single-story portal frame structure with two spans is constructed based on the transfer matrix method of multibody system (MS-TMM; both the transfer matrix of the components in the model and the total transfer matrix equation of the structure are derived, and the corresponding MATLAB program is compiled to determine the natural period and seismic response of the structure. The results show that the results based on the MS-TMM are similar to those obtained by ANSYS, but the calculation time of the MS-TMM method is only 1/20 of that of the ANSYS method. Additionally, it is shown that the MS-TMM method greatly increases the calculation efficiency while maintaining accuracy.
Lu, X.; Du, Z.; Schuur, E.; Luo, Y.
2017-12-01
Permafrost is one of the most vulnerable regions on the earth with over 40% world soil C represented in this region. Future climate warming potentially has a great impact on this region. On one hand, rising temperature accelerates permafrost soil thaw and release more C from land. On the other hand, warming may also increase the plant growing season length and therefore negatively feedback to climate change by increasing annual land C uptake. However, whether permafrost vegetation biomass change in response to warming can sequester more C has not been well understood. Manipulated air warming experiments reported that air warming has very limited impacts on grass land productivity and biomass growth in permafrost region [Mauritz et al., 2017]. It is hard to reveal the mechanisms behind the limited air warming response directly from experiment data. We employ a vegetation C cycle matrix model based on Community land model 4.5 (CLM4.5) and data assimilation technique to investigate how much do phenology and physiology processes contribute to the response respectively. Our results indicate phenology contributes the most in response to warming. The shift of vegetation parameter distributions after 2012 indicate vegetation acclimation may explain the modest response in plant biomass to air warming. The results suggest future model development need to take vegetation acclimation more seriously. The novel matrix-based model allows data assimilation to be conducted more efficiently. It provides more functional understanding of the models as well as the mechanism behind experiment data.
Energy Technology Data Exchange (ETDEWEB)
Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M.; Allafort, A.; Bechtol, K.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Borgland, A. W.; Bottacini, E. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Albert, A. [Department of Physics, Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, OH 43210 (United States); Atwood, W. B.; Bouvier, A. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Axelsson, M. [Department of Astronomy, Stockholm University, SE-106 91 Stockholm (Sweden); Baldini, L. [Universita di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Ballet, J. [Laboratoire AIM, CEA-IRFU/CNRS/Universite Paris Diderot, Service d' Astrophysique, CEA Saclay, F-91191 Gif sur Yvette (France); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bissaldi, E. [Institut fuer Astro- und Teilchenphysik and Institut fuer Theoretische Physik, Leopold-Franzens-Universitaet Innsbruck, A-6020 Innsbruck (Austria); Bonamente, E., E-mail: echarles@slac.stanford.edu, E-mail: luca.baldini@pi.infn.it, E-mail: rando@pd.infn.it [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); and others
2012-11-15
The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy {gamma}-ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission, the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the instrument response functions (IRFs), the description of the instrument performance provided for data analysis. In this paper, we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.
International Nuclear Information System (INIS)
Ackermann, M.; Ajello, M.; Allafort, A.; Bechtol, K.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Borgland, A. W.; Bottacini, E.; Albert, A.; Atwood, W. B.; Bouvier, A.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Bonamente, E.
2012-01-01
The Fermi Large Area Telescope (Fermi-LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy γ-ray telescope, covering the energy range from 20 MeV to more than 300 GeV. During the first years of the mission, the LAT team has gained considerable insight into the in-flight performance of the instrument. Accordingly, we have updated the analysis used to reduce LAT data for public release as well as the instrument response functions (IRFs), the description of the instrument performance provided for data analysis. In this paper, we describe the effects that motivated these updates. Furthermore, we discuss how we originally derived IRFs from Monte Carlo simulations and later corrected those IRFs for discrepancies observed between flight and simulated data. We also give details of the validations performed using flight data and quantify the residual uncertainties in the IRFs. Finally, we describe techniques the LAT team has developed to propagate those uncertainties into estimates of the systematic errors on common measurements such as fluxes and spectra of astrophysical sources.
DeBruler, Danielle M; Blackstone, Britani N; Baumann, Molly E; McFarland, Kevin L; Wulff, Brian C; Wilgus, Traci A; Bailey, J Kevin; Supp, Dorothy M; Powell, Heather M
2017-09-01
Fractional CO 2 laser therapy has been used to improve scar pliability and appearance; however, a variety of treatment protocols have been utilized with varied outcomes. Understanding the relationship between laser power and extent of initial tissue ablation and time frame for remodeling could help determine an optimum power and frequency for laser treatment. The characteristics of initial injury caused by fractional CO 2 laser treatment, the rates of dermal remodeling and re-epithelialization, and the extent of inflammation as a function of laser stacking were assessed in this study in a porcine scar model. Full-thickness burn wounds were created on female Red Duroc pigs followed by immediate excision of the eschar and split-thickness autografting. Three months after injury, the resultant scars were treated with a fractional CO 2 laser with 70 mJ of energy delivered as either a single pulse or stacked for three consecutive pulses. Immediately prior to laser treatment and at 1, 24, 96, and 168 hours post-laser treatment, transepidermal water loss (TEWL), erythema, and microscopic characteristics of laser injury were measured. In addition, markers for inflammatory cytokines, extracellular matrix proteins, and re-epithelialization were quantified at all time points using qRT-PCR. Both treatments produced erythema in the scar that peaked 24 hours after treatment then decreased to basal levels by 168 hours. TEWL increased after laser treatment and returned to normal levels between 24 and 96 hours later. Stacking of the pulses did not significantly increase the depth of ablated wells or extend the presence of erythema. Interleukin 6 and monocyte chemoattractant protein-1 were found to increase significantly 1 hour after treatment but returned to baseline by 24 hours post laser. In contrast, expression of transforming growth factor β1 and transforming growth factor β3 increased slowly after treatment with a more modest increase than interleukin 6 and monocyte
Sheets, Anthony R; Massey, Conner J; Cronk, Stephen M; Iafrati, Mark D; Herman, Ira M
2016-07-02
Non-healing wounds are a major global health concern and account for the majority of non-traumatic limb amputations worldwide. However, compared to standard care practices, few advanced therapeutics effectively resolve these injuries stemming from cardiovascular disease, aging, and diabetes-related vasculopathies. While matrix turnover is disrupted in these injuries, debriding enzymes may promote healing by releasing matrix fragments that induce cell migration, proliferation, and morphogenesis, and plasma products may also stimulate these processes. Thus, we created matrix- and plasma-derived peptides, Comb1 and UN3, which induce cellular injury responses in vitro, and accelerate healing in rodent models of non-healing wounds. However, the effects of these peptides in non-healing wounds in diabetes are not known. Here, we interrogated whether these peptides stimulate healing in a diabetic porcine model highly reminiscent of human healing impairments in type 1 and type 2-diabetes. After 3-6 weeks of streptozotocin-induced diabetes, full-thickness wounds were surgically created on the backs of adult female Yorkshire swine under general anesthesia. Comb1 and UN3 peptides or sterile saline (negative control) were administered to wounds daily for 3-7 days. Following sacrifice, wound tissues were harvested, and quantitative histological and immunohistochemical analyses were performed for wound closure, angiogenesis and granulation tissue deposition, along with quantitative molecular analyses of factors critical for angiogenesis, epithelialization, and dermal matrix remodeling. Comb1 and UN3 significantly increase re-epithelialization and angiogenesis in diabetic porcine wounds, compared to saline-treated controls. Additionally, fluorescein-conjugated Comb1 labels keratinocytes, fibroblasts, and vascular endothelial cells in porcine wounds, and Far western blotting reveals these cell populations express multiple fluorescein-Comb1-interacting proteins in vitro. Further
Niamsuwan, N.; Johnson, J. T.; Jezek, K. C.; Gogineni, P.
2008-12-01
The Global Ice Sheet Mapping Orbiter (GISMO) mission was developed to address scientific needs to understand the polar ice subsurface structure. This NASA Instrument Incubator Program project is a collaboration between Ohio State University, the University of Kansas, Vexcel Corporation and NASA. The GISMO design utilizes an interferometric SAR (InSAR) strategy in which ice sheet reflected signals received by a dual-antenna system are used to produce an interference pattern. The resulting interferogram can be used to filter out surface clutter so as to reveal the signals scattered from the base of the ice sheet. These signals are further processed to produce 3D-images representing basal topography of the ice sheet. In the past three years, the GISMO airborne field campaigns that have been conducted provide a set of useful data for studying geophysical properties of the Greenland ice sheet. While topography information can be obtained using interferometric SAR processing techniques, ice sheet roughness statistics can also be derived by a relatively simple procedure that involves analyzing power levels and the shape of the radar impulse response waveforms. An electromagnetic scattering model describing GISMO impulse responses has previously been proposed and validated. This model suggested that rms-heights and correlation lengths of the upper surface profile can be determined from the peak power and the decay rate of the pulse return waveform, respectively. This presentation will demonstrate a procedure for estimating the roughness of ice surfaces by fitting the GISMO impulse response model to retrieved waveforms from selected GISMO flights. Furthermore, an extension of this procedure to estimate the scattering coefficient of the glacier bed will be addressed as well. Planned future applications involving the classification of glacier bed conditions based on the derived scattering coefficients will also be described.
International Nuclear Information System (INIS)
Mitsuyasu, T.; Ishii, K.; Hino, T.; Aoyama, M.
2009-01-01
Spectral history methods for pin-by-pin core analysis method using the three-dimensional direct response matrix have been developed. The direct response matrix is formalized by four sub-response matrices in order to respond to a core eigenvalue k and thus can be recomposed at each outer iteration in the core analysis. For core analysis, it is necessary to take into account the burn-up effect related to spectral history. One of the methods is to evaluate the nodal burn-up spectrum obtained using the out-going neutron current. The other is to correct the fuel rod neutron production rates obtained the pin-by-pin correction. These spectral history methods were tested in a heterogeneous system. The test results show that the neutron multiplication factor error can be reduced by half during burn-up, the nodal neutron production rates errors can be reduced by 30% or more. The root-mean-square differences between the relative fuel rod neutron production rate distributions can be reduced within 1.1% error. This means that these methods can accurately reflect the effects of intra- and inter-assembly heterogeneities during burn-up and can be used for core analysis. Core analysis with the DRM method was carried out for an ABWR quarter core and it was found that both thermal power and coolant-flow distributions were smoothly converged. (authors)
Energy Technology Data Exchange (ETDEWEB)
Mansur, Ralph S.; Moura, Carlos A., E-mail: ralph@ime.uerj.br, E-mail: demoura@ime.uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Departamento de Engenharia Mecanica; Barros, Ricardo C., E-mail: rcbarros@pq.cnpq.br [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Departamento de Modelagem Computacional
2017-07-01
Presented here is an application of the Response Matrix (RM) method for adjoint discrete ordinates (S{sub N}) problems in slab geometry applied to energy-dependent source-detector problems. The adjoint RM method is free from spatial truncation errors, as it generates numerical results for the adjoint angular fluxes in multilayer slabs that agree with the numerical values obtained from the analytical solution of the energy multigroup adjoint SN equations. Numerical results are given for two typical source-detector problems to illustrate the accuracy and the efficiency of the offered RM computer code. (author)
Landau, Marina; Fagien, Steven
2015-11-01
Loss of viscoelasticity is one of the primarily signs of skin aging, followed by appearance of visible wrinkles. Hyaluronic acid (HA)-based fillers are widely used to fill wrinkles and compensate for volume loss. Recent clinical observations demonstrate persistence of the filling effect longer than the biological availability of the filler. Stimulation of new collagen by cross-linked HA and up-regulation of elastin have been suggested as possible explanation to this observation and have been supported experimentally. Cross-linked HA substitutes for fragmented collagen in restoring extracellular matrix required for normal activity of fibroblasts, such as collagen and elastin production. To restore extracellular matrix efficiently, serial monthly treatments are required. Boosting of facial and nonfacial skin through fibroblast activation is a new indication for HA-based products. Injectable HA has also been recently registered in Europe as agents specific for the improvement of skin quality (Restylane Skinboosters). Further explanation of the possible mechanisms supported by long-term clinical examples is presented herein.
Directory of Open Access Journals (Sweden)
Anatoliy Klimyk
2006-01-01
Full Text Available In the paper, properties of orbit functions are reviewed and further developed. Orbit functions on the Euclidean space E_n are symmetrized exponential functions. The symmetrization is fulfilled by a Weyl group corresponding to a Coxeter-Dynkin diagram. Properties of such functions will be described. An orbit function is the contribution to an irreducible character of a compact semisimple Lie group G of rank n from one of its Weyl group orbits. It is shown that values of orbit functions are repeated on copies of the fundamental domain F of the affine Weyl group (determined by the initial Weyl group in the entire Euclidean space E_n. Orbit functions are solutions of the corresponding Laplace equation in E_n, satisfying the Neumann condition on the boundary of F. Orbit functions determine a symmetrized Fourier transform and a transform on a finite set of points.
Optically induced anisotropy in photo responsive sol-gel matrix bearing a silylated disperse red 1
International Nuclear Information System (INIS)
Choi, Dong Hoon; Cho, Kang Jin; Cha, Young Kwan; Oh, Sang Joon
2000-01-01
We synthesized the simple triethoxysilanes (SGDR1) bearing a disperse red 1 for thin film fabrication. The thin films were prepared using the solution of SGDR1 after hydrolysis and condensation. The films were annealed at two different temperatures such as 150.deg.C and 200.deg.C. Trans-to-cis photoisomerization was observed under the exposure of 532 nm light with UV-Vis absorption spectroscopy. The kinetic study of photoisomerization was performed in the film. Reorientation of the polar azobenzene molecules induced optical anisotropy under a linearly polarized light at 532 nm. The effect of aggregation of the chromophores and annealing of the silicon oxide in the matrix were studied on the dynamic properties of isomerization and induced birefringence
Tarasov, Andrii; Rauhut, Doris; Jung, Rainer
2017-12-01
Analytical methods of haloanisoles and halophenols quantification in cork matrix are summarized in the current review. Sample-preparation and sample-treatment techniques have been compared and discussed from the perspective of their efficiency, time- and extractant-optimization, easiness of performance. Primary interest of these analyses usually addresses to 2,4,6-trichloroanisole (TCA), which is a major wine contaminant among haloanisoles. Two concepts of TCA determination are described in the review: releasable TCA and total TCA analyses. Chromatographic, bioanalytical and sensorial methods were compared according to their application in the cork industry and in scientific investigations. Finally, it was shown that modern analytical techniques are able to provide required sensitivity, selectivity and repeatability for haloanisoles and halophenols determination. Copyright © 2017 Elsevier B.V. All rights reserved.
Responsibility modulates pain-matrix activation elicited by the expressions of others in pain
Cui, Fang; Abdelgabar, Abdel-Rahman; Keysers, Christian; Gazzola, Valeria
2015-01-01
Here we examine whether brain responses to dynamic facial expressions of pain are influenced by our responsibility for the observed pain. Participants played a flanker task with a confederate. Whenever either erred, the confederate was seen to receive a noxious shock. Using functional magnetic
Cellular and Matrix Response of the Mandibular Condylar Cartilage to Botulinum Toxin.
Directory of Open Access Journals (Sweden)
Eliane H Dutra
Full Text Available To evaluate the cellular and matrix effects of botulinum toxin type A (Botox on mandibular condylar cartilage (MCC and subchondral bone.Botox (0.3 unit was injected into the right masseter of 5-week-old transgenic mice (Col10a1-RFPcherry at day 1. Left side masseter was used as intra-animal control. The following bone labels were intraperitoneally injected: calcein at day 7, alizarin red at day 14 and calcein at day 21. In addition, EdU was injected 48 and 24 hours before sacrifice. Mice were sacrificed 30 days after Botox injection. Experimental and control side mandibles were dissected and examined by x-ray imaging and micro-CT. Subsequently, MCC along with the subchondral bone was sectioned and stained with tartrate resistant acid phosphatase (TRAP, EdU, TUNEL, alkaline phosphatase, toluidine blue and safranin O. In addition, we performed immunohistochemistry for pSMAD and VEGF.Bone volume fraction, tissue density and trabecular thickness were significantly decreased on the right side of the subchondral bone and mineralized cartilage (Botox was injected when compared to the left side. There was no significant difference in the mandibular length and condylar head length; however, the condylar width was significantly decreased after Botox injection. Our histology showed decreased numbers of Col10a1 expressing cells, decreased cell proliferation and increased cell apoptosis in the subchondral bone and mandibular condylar cartilage, decreased TRAP activity and mineralization of Botox injected side cartilage and subchondral bone. Furthermore, we observed reduced proteoglycan and glycosaminoglycan distribution and decreased expression of pSMAD 1/5/8 and VEGF in the MCC of the Botox injected side in comparison to control side.Injection of Botox in masseter muscle leads to decreased mineralization and matrix deposition, reduced chondrocyte proliferation and differentiation and increased cell apoptosis in the MCC and subchondral bone.
Backstrom, Kristin C; Bertone, Alicia L; Wisner, Erik R; Weisbrode, Stephen E
2004-09-01
To determine whether human parathyroid hormone (hPTH) gene in collagen matrix could safely promote bone formation in diaphyseal or subchondral bones of horses. 8 clinically normal adult horses. Amount, rate, and quality of bone healing for 13 weeks were determined by use of radiography, quantitative computed tomography, and histomorphometric analysis. Diaphyseal cortex and subchondral bone defects of metacarpi were filled with hPTH(1-34) gene-activated matrix (GAM) or remained untreated. Joints were assessed on the basis of circumference, synovial fluid analysis, pain on flexion, lameness, and gross and histologic examination. Bone volume index was greater for cortical defects treated with hPTH(1-34) GAM, compared with untreated defects. Bone production in cortical defects treated with hPTH(1-34) GAM positively correlated with native bone formation in untreated defects. In contrast, less bone was detected in hPTH(1-34) GAM-treated subchondral bone defects, compared with untreated defects, and histology confirmed poorer healing and residual collagen sponge. Use of hPTH(1-34) GAM induced greater total bone, specifically periosteal bone, after 13 weeks of healing in cortical defects of horses. The hPTH(1-34) GAM impeded healing of subchondral bone but was biocompatible with joint tissues. Promotion of periosteal bone formation may be beneficial for healing of cortical fractures in horses, but the delay in onset of bone formation may negate benefits. The hPTH(1-34) GAM used in this study should not be placed in articular subchondral bone defects, but contact with articular surfaces is unlikely to cause short-term adverse effects.
Clement, T Prabhakar
2014-06-01
We propose a rational method for addressing an important question-who deserves to be an author of a scientific article? We review various contentious issues associated with this question and recommend that the scientific community should view authorship in terms of contributions and responsibilities, rather than credits. We propose a new paradigm that conceptually divides a scientific article into four basic elements: ideas, work, writing, and stewardship. We employ these four fundamental elements to modify the well-known International Committee of Medical Journal Editors (ICMJE) authorship guidelines. The modified ICMJE guidelines are then used as the basis to develop an approach to quantify individual contributions and responsibilities in multi-author articles. The outcome of the approach is an authorship matrix, which can be used to answer several nagging questions related to authorship.
Cramer, Gwendolyn; El-Hamidi, Hamid; Jafari, Seyedehrojin; Jones, Dustin P.; Celli, Jonathan P.
2016-03-01
The composition and mechanical compliance of the extracellular matrix (ECM) have been shown to serve as regulators of tumor growth and invasive behavior. These effects may be particularly relevant in tumors of the pancreas, noted for a profound desmoplastic reaction and an abundance of stroma rich in ECM. In view of recent progress in the clinical implementation of photodynamic therapy (PDT) for pancreatic tumors, in this report we examine how ECM composition and rheological properties impact upon invasive behavior and response to PDT in 3D multicellular pancreatic tumor spheroids in ECM environments with characterized rheological properties. Tumor spheroids were cultured initially in attachment-free conditions to form millimeter-sized spheroids that were transplanted into reconstituted ECM microenvironments (Matrigel and Type I Collagen) that were characterized using bulk oscillatory shear rheology. Analysis of growth behavior shows that the soft collagen ECM promoted growth and extensive invasion and this microenvironment was used in subsequent assessment of PDT and chemotherapy response. Evaluation of treatment response revealed that primary tumor nodule growth is inhibited more effectively with PDT, while verteporfin PDT response is significantly enhanced in the ECM-infiltrating populations that are non-responsive to oxaliplatin chemotherapy. This finding is potentially significant, suggesting the potential for PDT to target these clinically problematic invasive populations that are associated with aggressive metastatic progression and chemoresistance. Experiments to further validate and identify the mechanistic basis of this observation are ongoing.
Koo, Hyeon-Kyoung; Hong, Yoonki; Lim, Myoung Nam; Yim, Jae-Joon; Kim, Woo Jin
2016-01-01
Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation in the airway and lung. A protease-antiprotease imbalance has been suggested as a possible pathogenic mechanism for COPD. We evaluated the relationship between matrix metalloproteinase (MMP) levels and COPD severity. Plasma levels of MMP-1, MMP-8, MMP-9, and MMP-12 were measured in 57 COPD patients and 36 normal controls. The relationship between MMP levels and lung function, emphysema index, bronchial wall thickness, pulmonary artery pressure, and quality of life was examined using general linear regression analyses. There were significant associations of MMP-1 with bronchodilator reversibility and of MMP-8 and MMP-9 with lung function. Also, MMP-1, MMP-8, and MMP-9 levels were correlated with the emphysema index, independent of lung function. However, MMP-12 was not associated with lung function or emphysema severity. Associations between MMP levels and bronchial wall thickness, pulmonary artery pressure, and quality of life were not statistically significant. Plasma levels of MMP-1, MMP-8, and MMP-9 are associated with COPD severity and can be used as a biomarker to better understand the characteristics of COPD patients.
Vieira Ramos, Gracielle; Pinheiro, Clara Maria; Messa, Sabrina Peviani; Delfino, Gabriel Borges; Marqueti, Rita de Cássia; Salvini, Tania de Fátima; Durigan, Joao Luiz Quagliotti
2016-01-04
The application of cryotherapy is widely used in sports medicine today. Cooling could minimize secondary hypoxic injury through the reduction of cellular metabolism and injury area. Conflicting results have also suggested cryotherapy could delay and impair the regeneration process. There are no definitive findings about the effects of cryotherapy on the process of muscle regeneration. The aim of the present study was to evaluate the effects of a clinical-like cryotherapy on inflammation, regeneration and extracellular matrix (ECM) remodeling on the Tibialis anterior (TA) muscle of rats 3, 7 and 14 days post-injury. It was observed that the intermittent application of cryotherapy (three 30-minute sessions, every 2 h) in the first 48 h post-injury decreased inflammatory processes (mRNA levels of TNF-α, NF-κB, TGF-β and MMP-9 and macrophage percentage). Cryotherapy did not alter regeneration markers such as injury area, desmin and Myod expression. Despite regulating Collagen I and III and their growth factors, cryotherapy did not alter collagen deposition. In summary, clinical-like cryotherapy reduces the inflammatory process through the decrease of macrophage infiltration and the accumulation of the inflammatory key markers without influencing muscle injury area and ECM remodeling.
Mouriaux, F; Coffin-Pichonnet, S; Robert, P-Y; Abad, S; Martin-Silva, N
2014-12-01
Orbital inflammation is a generic term encompassing inflammatory pathologies affecting all structures within the orbit : anterior (involvement up to the posterior aspect of the globe), diffuse (involvement of intra- and/or extraconal fat), apical (involvement of the posterior orbit), myositis (involvement of only the extraocular muscles), dacryoadenitis (involvement of the lacrimal gland). We distinguish between specific inflammation and non-specific inflammation, commonly referred to as idiopathic inflammation. Specific orbital inflammation corresponds to a secondary localization of a "generalized" disease (systemic or auto-immune). Idiopathic orbital inflammation corresponds to uniquely orbital inflammation without generalized disease, and thus an unknown etiology. At the top of the differential diagnosis for specific or idiopathic orbital inflammation are malignant tumors, represented most commonly in the adult by lympho-proliferative syndromes and metastases. Treatment of specific orbital inflammation begins with treatment of the underlying disease. For idiopathic orbital inflammation, treatment (most often corticosteroids) is indicated above all in cases of visual loss due to optic neuropathy, in the presence of pain or oculomotor palsy. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
Goody, Michelle F; Sher, Roger B; Henry, Clarissa A
2015-05-01
Skeletal muscle specification and morphogenesis during early development are critical for normal physiology. In addition to mediating locomotion, skeletal muscle is a secretory organ that contributes to metabolic homeostasis. Muscle is a highly adaptable tissue, as evidenced by the ability to increase muscle cell size and/or number in response to weight bearing exercise. Conversely, muscle wasting can occur during aging (sarcopenia), cancer (cancer cachexia), extended hospital stays (disuse atrophy), and in many genetic diseases collectively known as the muscular dystrophies and myopathies. It is therefore of great interest to understand the cellular and molecular mechanisms that mediate skeletal muscle development and adaptation. Muscle morphogenesis transforms short muscle precursor cells into long, multinucleate myotubes that anchor to tendons via the myotendinous junction. This process requires carefully orchestrated interactions between cells and their extracellular matrix microenvironment. These interactions are dynamic, allowing muscle cells to sense biophysical, structural, organizational, and/or signaling changes within their microenvironment and respond appropriately. In many musculoskeletal diseases, these cell adhesion interactions are disrupted to such a degree that normal cellular adaptive responses are not sufficient to compensate for accumulating damage. Thus, one major focus of current research is to identify the cell adhesion mechanisms that drive muscle morphogenesis, with the hope that understanding how muscle cell adhesion promotes the intrinsic adaptability of muscle tissue during development may provide insight into potential therapeutic approaches for muscle diseases. Our objectives in this review are to highlight recent studies suggesting conserved roles for cell-extracellular matrix adhesion in vertebrate muscle morphogenesis and cellular adaptive responses in animal models of muscle diseases. Copyright © 2015 Elsevier Inc. All rights
Directory of Open Access Journals (Sweden)
D Kuraitis
2011-09-01
Full Text Available Although many regenerative cell therapies are being developed to replace or regenerate ischaemic muscle, the lack of vasculature and poor persistence of the therapeutic cells represent major limiting factors to successful tissue restoration. In response to ischaemia, stromal cell-derived factor-1 (SDF-1 is up-regulated by the affected tissue to stimulate stem cell-mediated regenerative responses. Therefore, we encapsulated SDF-1 into alginate microspheres and further incorporated these into an injectable collagen-based matrix in order to improve local delivery. Microsphere-matrix impregnation reduced the time for matrix thermogelation, and also increased the viscosity reached. This double-incorporation prolonged the release of SDF-1, which maintained adhesive and migratory bioactivity, attributed to chemotaxis in response to SDF-1. In vivo, treatment of ischaemic hindlimb muscle with microsphere-matrix led to increased mobilisation of bone marrow-derived progenitor cells, and also improved recruitment of angiogenic cells expressing the SDF-1 receptor (CXCR4 from bone marrow and local tissues. Both matrix and SDF-1-releasing matrix were successful at restoring perfusion, but SDF-1 treatment appeared to play an earlier role, as evidenced by arterioles that are phenotypically older and by increased angiogenic cytokine production, stimulating the generation of a qualitative microenvironment for a rapid and therefore more efficient regeneration. These results support the release of implanted SDF-1 as a promising method for enhancing progenitor cell responses and restoring perfusion to ischaemic tissues via neovascularisation.
Directory of Open Access Journals (Sweden)
Ikrima Khalid
2014-09-01
Full Text Available The objective of the current study was to formulate mucoadhesive controlled release matrix tablets of flurbiprofen and to optimize its drug release profile and bioadhesion using response surface methodology. Tablets were prepared via a direct compression technique and evaluated for in vitro dissolution parameters and bioadhesive strength. A central composite design for two factors at five levels each was employed for the study. Carbopol 934 and sodium carboxymethylcellulose were taken as independent variables. Fourier transform infrared (FTIR spectroscopy studies were performed to observe the stability of the drug during direct compression and to check for a drug-polymer interaction. Various kinetic models were applied to evaluate drug release from the polymers. Contour and response surface plots were also drawn to portray the relationship between the independent and response variables. Mucoadhesive tablets of flurbiprofen exhibited non-Fickian drug release kinetics extending towards zero-order, with some formulations (F3, F8, and F9 reaching super case II transport, as the value of the release rate exponent (n varied between 0.584 and 1.104. Polynomial mathematical models, generated for various response variables, were found to be statistically significant (P<0.05. The study also helped to find the drug's optimum formulation with excellent bioadhesive strength. Suitable combinations of two polymers provided adequate release profile, while carbopol 934 produced more bioadhesion.
Pindera, Marek-Jerzy; Salzar, Robert S.; Williams, Todd O.
1993-01-01
The utility of a recently developed analytical micromechanics model for the response of metal matrix composites under thermal loading is illustrated by comparison with the results generated using the finite-element approach. The model is based on the concentric cylinder assemblage consisting of an arbitrary number of elastic or elastoplastic sublayers with isotropic or orthotropic, temperature-dependent properties. The elastoplastic boundary-value problem of an arbitrarily layered concentric cylinder is solved using the local/global stiffness matrix formulation (originally developed for elastic layered media) and Mendelson's iterative technique of successive elastic solutions. These features of the model facilitate efficient investigation of the effects of various microstructural details, such as functionally graded architectures of interfacial layers, on the evolution of residual stresses during cool down. The available closed-form expressions for the field variables can readily be incorporated into an optimization algorithm in order to efficiently identify optimal configurations of graded interfaces for given applications. Comparison of residual stress distributions after cool down generated using finite-element analysis and the present micromechanics model for four composite systems with substantially different temperature-dependent elastic, plastic, and thermal properties illustrates the efficacy of the developed analytical scheme.
A Bayesian method to estimate the neutron response matrix of a single crystal CVD diamond detector
International Nuclear Information System (INIS)
Reginatto, Marcel; Araque, Jorge Guerrero; Nolte, Ralf; Zbořil, Miroslav; Zimbal, Andreas; Gagnon-Moisan, Francis
2015-01-01
Detectors made from artificial chemical vapor deposition (CVD) single crystal diamond are very promising candidates for applications where high resolution neutron spectrometry in very high neutron fluxes is required, for example in fusion research. We propose a Bayesian method to estimate the neutron response function of the detector for a continuous range of neutron energies (in our case, 10 MeV ≤ E n ≤ 16 MeV) based on a few measurements with quasi-monoenergetic neutrons. This method is needed because a complete set of measurements is not available and the alternative approach of using responses based on Monte Carlo calculations is not feasible. Our approach uses Bayesian signal-background separation techniques and radial basis function interpolation methods. We present the analysis of data measured at the PTB accelerator facility PIAF. The method is quite general and it can be applied to other particle detectors with similar characteristics
Iyer, Rugmani Padmanabhan; Jung, Mira; Lindsey, Merry L
Following myocardial infarction (MI), the left ventricle (LV) undergoes a series of molecular, cellular, and functional alterations that are both part of the wound healing response to form a scar in the infarct region and the consequence of that response. Using the laws of thermodynamics as an analogy, we present here three laws for categorizing the post-MI LV remodeling process. The first law is that the LV will attempt to maintain equilibrium and compensate as a way to maximize function, the second law is that remodeling is progressive and unidirectional, and the third law is that the final goal is (ideally, but not always achievable) a stable, equilibrated scar. This comparison helps to define the boundaries of the system, whether it be the infarct zone, the LV, the heart, or the entire body. This review provides an overview for those not directly in the field and establishes a framework to help prioritize future research directions.
International Nuclear Information System (INIS)
Kim, Jeong Soo; Kim, Moon Kyum
2012-01-01
In this study, finite element analysis of beam on elastic foundation, which received great attention of researchers due to its wide applications in engineering, is performed for estimating dynamic responses of shallow foundation using exact stiffness matrix. First, element stiffness matrix based on the closed solution of beam on elastic foundation is derived. Then, we performed static finite element analysis included exact stiffness matrix numerically, comparing results from the analysis with some exact analysis solutions well known for verification. Finally, dynamic finite element analysis is performed for a shallow foundation structure under rectangular pulse loading using trapezoidal method. The dynamic analysis results exist in the reasonable range comparing solution of single degree of freedom problem under a similar condition. The results show that finite element analysis using exact stiffness matrix is evaluated as a good tool of estimating the dynamic response of structures on elastic foundation.
DEFF Research Database (Denmark)
Jørgensen, Peter; Rattan, Suresh
2014-01-01
recent observations indicate that replicative lifespan, senescence and functionality of cells in vitro can be significantly affected by the quality of the extra cellular matrix (ECM). Following up on those reports, here we show that using the ECM prepared from early passage young cells, partial...... rejuvenation of serially passaged human facial skin fibroblasts was possible in pre-senescent middle-aged cells, but not in fully senescent late passage cells. ECM from young cells improved the appearance, viability, stress tolerance and wound healing ability of skin fibroblasts. Furthermore, young ECM...... modulated the oxidative stress response transcription factor Nrf-2 and its downstream effector haem-oxygenase (HO-1), possibly through the amelioration of the environmental stress induced by the plastic surface of the culturing flasks. Therefore, it is important to consider the role of ECM in modulating...
Kiser, J. Douglas; Bansal, Narottam P.; Szelagowski, James; Sokhey, Jagdish; Heffernan, Tab; Clegg, Joseph; Pierluissi, Anthony; Riedell, Jim; Wyen, Travis; Atmur, Steven;
2015-01-01
LibertyWorks®, a subsidiary of Rolls-Royce Corporation, first studied CMC (ceramic matrix composite) exhaust mixers for potential weight benefits in 2008. Oxide CMC potentially offered weight reduction, higher temperature capability, and the ability to fabricate complex-shapes for increased mixing and noise suppression. In 2010, NASA was pursuing the reduction of NOx emissions, fuel burn, and noise from turbine engines in Phase I of the Environmentally Responsible Aviation (ERA) Project (within the Integrated Systems Research Program). ERA subtasks, including those focused on CMC components, were being formulated with the goal of maturing technology from Proof of Concept Validation (Technology Readiness Level 3 (TRL 3)) to System/Subsystem or Prototype Demonstration in a Relevant Environment (TRL 6). LibertyWorks®, a subsidiary of Rolls-Royce Corporation, first studied CMC (ceramic matrix composite) exhaust mixers for potential weight benefits in 2008. Oxide CMC potentially offered weight reduction, higher temperature capability, and the ability to fabricate complex-shapes for increased mixing and noise suppression. In 2010, NASA was pursuing the reduction of NOx emissions, fuel burn, and noise from turbine engines in Phase I of the Environmentally Responsible Aviation (ERA) Project (within the Integrated Systems Research Program). ERA subtasks, including those focused on CMC components, were being formulated with the goal of maturing technology from Proof of Concept Validation (Technology Readiness Level 3 (TRL 3)) to System/Subsystem or Prototype Demonstration in a Relevant Environment (TRL 6). Oxide CMC component at both room and elevated temperatures. A TRL˜5 (Component Validation in a Relevant Environment) was attained and the CMC mixer was cleared for ground testing on a Rolls-Royce AE3007 engine for performance evaluation to achieve TRL 6.
Feasibility of a responsive, hybrid propulsion augmented, Vertical-Takeoff-and-Landing, Single-Stage-to-Orbit launch system
Pelaccio, Dennis G.
1996-03-01
A novel, reusable, Vertical-Takeoff-and-Landing, Single-Stage-to-Orbit (VTOL/SSTO) launch system concept, named HYP-SSTO, is presented in this paper. This launch vehicle system concept uses a highly coupled, main high performance liquid oxygen/liquid hydrogen (LOX/LH2) propulsion system, that is used only for launch, with a hybrid auxiliary propulsion system which is used during final orbit insertion, major orbit maneuvering, and landing propulsive burn phases of flight. By using a hybrid propulsion system for major orbit maneuver burns and landing, this launch system concept has many advantages over conventional VTOL/SSTO concepts that use LOX/LH2 propulsion system(s) burns for all phases of flight. Because hybrid propulsion systems are relatively simple and inert by their nature, this concept has the potential to support short turnaround times between launches, be economical to develop, and be competitive in terms of overall system life-cycle cost. This paper provides a technical description of the novel, reusable HYP-SSTO launch system concept. Launch capability performance, as well as major design and operational system attributes, are identified and discussed.
Quark Orbital Angular Momentum
Directory of Open Access Journals (Sweden)
Burkardt Matthias
2015-01-01
Full Text Available Definitions of orbital angular momentum based on Wigner distributions are used as a framework to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. We find that the difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.
Sol, Jeroen A H P; Dehm, Volker; Hecht, Reinhard; Würthner, Frank; Schenning, Albertus P H J; Debije, Michael G
2018-01-22
Temperature-responsive luminescent solar concentrators (LSCs) have been fabricated in which the Förster resonance energy transfer (FRET) between a donor-acceptor pair in a liquid crystalline solvent can be tuned. At room temperatures, the perylene bisimide (PBI) acceptor is aggregated and FRET is inactive; while after heating to a temperature above the isotropic phase of the liquid crystal solvent, the acceptor PBI completely dissolves and FRET is activated. This unusual temperature control over FRET was used to design a color-tunable LSC. The device has been shown to be highly stable towards consecutive heating and cooling cycles, making it an appealing device for harvesting otherwise unused solar energy. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
International Nuclear Information System (INIS)
Rzepecki, R.; Markiewicz, E.; Szopa, J.
1995-01-01
The nuclear matrices from White bush (''Cucurbita pepo var. patisonina'') cell nuclei have been isolated using three methods: I, standard procedure involving extraction of cell nuclei with 2 M NaCl and 1% Triton X-100; II, the same with pre-treatment of cell nuclei with 0.5 mM CuSO 4 (stabilisation step); and III, method with extraction by lithium diiodosalicylate (LIS), and compared the polypeptide pattern. The isolated matrices specifically bind SAR DNA derived from human β-interferon gene in the exogenous SAR binding assay and in the gel mobility shift assay. Using IgG against the 32 kDa endonuclease we have found in the DNA-protein blot assay that this protein is one of the proteins binding SAR DNA. We have identified three proteins with molecular mass of 65 kDa, 60 kDa and 32 kDa which are responsible for SAR DNA binding in the gel mobility shift assay experiments. (author). 21 refs, 3 figs
Alginate/sodium caseinate aqueous-core capsules: a pH-responsive matrix.
Ben Messaoud, Ghazi; Sánchez-González, Laura; Jacquot, Adrien; Probst, Laurent; Desobry, Stéphane
2015-02-15
Alginate capsules have several applications. Their functionality depends considerably on their permeability, chemical and mechanical stability. Consequently, the creation of composite system by addition of further components is expected to control mechanical and release properties of alginate capsules. Alginate and alginate-sodium caseinate composite liquid-core capsules were prepared by a simple extrusion. The influence of the preparation pH and sodium caseinate concentration on capsules physico-chemical properties was investigated. Results showed that sodium caseinate influenced significantly capsules properties. As regards to the membrane mechanical stability, composite capsules prepared at pH below the isoelectric point of sodium caseinate exhibited the highest surface Young's modulus, increasing with protein content, explained by potential electrostatic interactions between sodium caseinate amino-groups and alginate carboxylic group. The kinetic of cochineal red A release changed significantly for composite capsules and showed a pH-responsive release. Sodium caseinate-dye mixture studied by absorbance and fluorescence spectroscopy confirmed complex formation at pH 2 by electrostatic interactions between sodium caseinate tryptophan residues and cochineal red sulfonate-groups. Consequently, the release mechanism was explained by membrane adsorption process. This global approach is useful to control release mechanism from macro and micro-capsules by incorporating guest molecules which can interact with the entrapped molecule under specific conditions. Copyright © 2014 Elsevier Inc. All rights reserved.
Vu, Hong; Shulenin, Sergey; Grolla, Allen; Audet, Jonathan; He, Shihua; Kobinger, Gary; Unfer, Robert C; Warfield, Kelly L; Aman, M Javad; Holtsberg, Frederick W
2016-02-01
The West Africa Ebola virus disease (EVD) outbreak has reached unprecedented magnitude and caused worldwide concerns for the spread of this deadly virus. Recent findings in nonhuman primates (NHPs) demonstrate that antibodies can be protective against EVD. However, the role of antibody response in vaccine-mediated protection is not fully understood. To address these questions quantitative serology assays are needed for measurement of the antibody response to key Ebola virus (EBOV) proteins. Serology enzyme-linked immunosorbent assays (ELISA's), using a reference detection antibody, were developed in order to standardize the quantitation of antibody levels in vaccinated NHPs or in humans exposed to EBOV or immunized with an EBOV vaccine. Critical reagents were generated to support the development of the serology ELISAs. Recombinant EBOV matrix protein (VP40) was expressed in Escherichia coli and purified. Two variants of the glycoprotein (GP), the ectodomain lacking the transmembrane domain (GPΔTM), and an engineered GP lacking the mucin-like domain (GPΔmuc) were expressed and purified from mammalian cell systems. Using these proteins, three ELISA methods were developed and optimized for reproducibility and robustness, including stability testing of critical reagents. The assay was used to determine the antibody response against VP40, GPΔTM, and GPΔmuc in a NHP vaccine study using EBOV virus-like particles (VLP) vaccine expressing GP, VP40 and the nucleoprotein. Additionally, these ELISAs were used to successfully detect antibody responses to VP40, GPΔTM and GPΔmuc in human sera from EBOV infected individuals. Copyright © 2015 Elsevier B.V. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Choi, Jin Kyeong [Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Molecular Immunology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Kim, Sung-Wan; Kim, Duk-Sil [Department of Thoracic and Cardiovascular Surgery, CHA Gumi Medical Center, CHA University, Gumi 730-040 (Korea, Republic of); Lee, Jong Yeong [Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Lee, Soyoung [Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Bio-Materials Research Institute, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 580-185 (Korea, Republic of); Oh, Hyun-Mee [Bio-Materials Research Institute, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 580-185 (Korea, Republic of); Ha, Yeong Su; Yoo, Jeongsoo [Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Park, Pil-Hoon [College of Pharmacy, Yeungnam University, Gyeongbuk 712-749 (Korea, Republic of); Shin, Tae-Yong [College of Pharmacy, Woosuk University, Jeonju 565-701 (Korea, Republic of); Kwon, Taeg Kyu [Department of Immunology, School of Medicine, Keimyung University, Daegu 704-701 (Korea, Republic of); Rho, Mun-Chual, E-mail: rho-m@kribb.re.kr [Bio-Materials Research Institute, Korea Research Institute of Bioscience and Biotechnology, Jeongeup 580-185 (Korea, Republic of); Kim, Sang-Hyun, E-mail: shkim72@knu.ac.kr [Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of)
2016-01-01
ABSTRACT: Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with a combination of synovium joint inflammation, synovium hyperplasia, and destruction of cartilage and bone. Oleanolic acid acetate (OAA), a compound isolated from Vigna angularis, has been known to possess pharmacological activities, including anti-inflammation and anti-bone destruction. In this study, we investigated the effects of OAA on RA and the underlying mechanisms of action by using a type-II collagen-induced arthritis (CIA) mouse model and tumor necrosis factor (TNF)-α-stimulated RA synovial fibroblasts. Oral administration of OAA decreased the clinical arthritis symptoms, paw thickness, histologic and radiologic changes, and serum total and anti-type II collagen IgG, IgG1, and IgG2a levels. OAA administration reduced Th1/Th17 phenotype CD4{sup +} T lymphocyte expansions and inflammatory cytokine productions in T cell activated draining lymph nodes and spleen. OAA reduced the expression and production of inflammatory mediators, such as cytokines and matrix metalloproteinase (MMP)-1/3, in the ankle joint tissue and RA synovial fibroblasts by down-regulating Akt, mitogen-activated protein kinases, and nuclear factor-κB. Our results clearly support that OAA plays a therapeutic role in RA pathogenesis by modulating helper T cell immune responses and matrix-degrading enzymes. The immunosuppressive effects of OAA were comparable to dexamethasone and ketoprofen. We provide evidences that OAA could be a potential therapeutic candidate for RA. - Highlights: • OAA attenuated chronic CIA symptoms. • OAA had a regulating effect on the T helper cell immune reaction for CIA. • The effect of OAA on the RA was comparable to the dexamethasone or ketoprofen. • OAA might be a candidate for the treatment of arthritic diseases.
International Nuclear Information System (INIS)
Leal A, B.; Mireles G, F.; Quirino T, L.; Pinedo, J.L.
2005-01-01
In the area of the Radiological Safety it is required of a calibrated detection system in energy and efficiency for the determination of the concentration in activity in samples that vary in chemical composition and by this in density. The area of Nuclear Engineering requires to find the grade of isotopic enrichment of the uranium of the Sub-critic Nuclear Chicago 9000 Mark. Given the experimental importance that has the determination from the curves of efficiency to the effects of establishing the quantitative results, is appealed to the simulation of the response function of the detector used in the Regional Center of Nuclear Studies inside the range of energy of 80 keV to 1400 keV varying the density of the matrix and the chemical composition by means of the application of the Monte Carlo code MCNP-4A. The obtained results in the simulation of the response function of the detector show a grade of acceptance in the range from 500 to 1400 keV energy, with a smaller percentage discrepancy to 10%, in the range of low energy that its go from 59 to 400 keV, the percentage discrepancy varies from 17% until 30%, which is manifested in the opposing isotopic relationship for 5 fuel rods of the Sub critic nuclear assemble. (Author)
Qu, Jian-Bo; Xu, Yu-Liang; Liu, Jun-Yi; Zeng, Jing-Bin; Chen, Yan-Li; Zhou, Wei-Qing; Liu, Jian-Guo
2016-04-08
Dual thermo- and pH-responsive chromatography has been proposed using poly(N-isopropylacrylamide-co-butyl methacrylate-co-N,N-dimethylaminopropyl acrylamide) (P(NIPAM-co-BMA-co-DMAPAAM)) brushes grafted gigaporous polystyrene microspheres (GPM) as matrix. Atom transfer radical polymerization (ATRP) initiator was first coupled onto GPM through Friedel-Crafts acylation with 2-bromoisobutyryl bromide. The dual-responsive polymer brushes were then grafted onto GPM via surface-initiated ATRP. The surface composition, gigaporous structure, protein adsorption and dual-responsive chromatographic properties of the matrix (GPM-P(NIPAM-co-BMA-co-DMAPAAM) were characterized in detail. Results showed that GPM were successfully grafted with thermoresponsive cationic polymer brushes and that the gigaporous structure was well maintained. A column packed with GPM-P(NIPAM-co-BMA-co-DMAPAAM presented low backpressure, good permeability and appreciable thermo-responsibility. By changing pH of the mobile phase and temperature of the column in turn, the column can separate three model proteins at the mobile phase velocity up to 2528cmh(-1). A separation mechanism of this matrix was also proposed. All results indicate that the dual thermo- and pH-responsive chromatography matrix has great potentials in 'green' high-speed protein chromatography. Copyright © 2016 Elsevier B.V. All rights reserved.
DEFF Research Database (Denmark)
Colombo, Stefano; Brisander, Magnus; Haglöf, Jakob
2015-01-01
Factors determining the pH-controlled dissolution kinetics of nilotinib formulations with the pH-titrable polymer hydroxypropyl methylcellulose phthalate, obtained by carbon dioxide-mediated precipitation, were mechanistically examined in acid and neutral environment. The matrix effect, modulating...... in the polymer matrix were mediated by hydrogen bonding between the drug and the phthalate groups on the polymer. Simultaneous Raman and UV-imaging studies of the effect of drug load on the swelling and dissolution of the polymer matrix revealed that high nilotinib load prevented matrix swelling on passage from...
International Nuclear Information System (INIS)
Oertel, H. Jr.; Koerner, H.
1993-01-01
The Third Aerospace Symposium in Braunschweig presented, for the first time, the possibility of bringing together the classical disciplines of aerospace engineering and the natural science disciplines of meteorology and air chemistry in a european setting. In this way, aspects of environmental impact on the atmosphere could be examined quantitatively. An essential finding of the european conference, is the unrestricted agreement of the experts that the given launch frequencies of the present orbital transport result in a negligible amount of pollutants being released in the atmosphere. The symposium does, however, call attention to the increasing need to consider the effect of orbital and atmospheric environmental impact of a future increase in launch frequencies of orbital transport in connection with future space stations. The Third Aerospace Symposium, 'Orbital Transport, Technical, Meteorological and Chemical Aspects', constituted a first forum of discussion for engineers and scientists. Questions of new orbital transport technologies and their environmental impact were to be discussed towards a first consensus. Through the 34 reports and articles, the general problems of space transportation and environmental protection were addressed, as well as particular aspects of high temperatures during reentry in the atmosphere of the earth, precision navigation of flight vehicles or flow behavior and air chemistry in the stratosphere. (orig./CT). 342 figs
Directory of Open Access Journals (Sweden)
Daolun Li
2015-01-01
Full Text Available A mathematical dual porosity and dual permeability numerical model based on perpendicular bisection (PEBI grid is developed to describe gas flow behaviors in shale-gas reservoirs by incorporating slippage corrected permeability and adsorbed gas effect. Parametric studies are conducted for a horizontal well with multiple infinite conductivity hydraulic fractures in shale-gas reservoir to investigate effect of matrix-wellbore flow, natural fracture porosity, and matrix porosity. We find that the ratio of fracture permeability to matrix permeability approximately decides the bottom hole pressure (BHP error caused by omitting the flow between matrix and wellbore and that the effect of matrix porosity on BHP is related to adsorption gas content. When adsorbed gas accounts for large proportion of the total gas storage in shale formation, matrix porosity only has a very small effect on BHP. Otherwise, it has obvious influence. This paper can help us understand the complex pressure transient response due to existence of the adsorbed gas and help petroleum engineers to interpret the field data better.
Frank, Marius S.; Hättig, Christof
2018-04-01
We present a pair natural orbital (PNO)-based implementation of coupled cluster singles and doubles (CCSD) excitation energies that builds upon the previously proposed state-specific PNO approach to the excited state eigenvalue problem. We construct the excited state PNOs for each state separately in a truncated orbital specific virtual basis and use a local density-fitting approximation to achieve an at most quadratic scaling of the computational costs for the PNO construction. The earlier reported excited state PNO construction is generalized such that a smooth convergence of the results for charge transfer states is ensured for general coupled cluster methods. We investigate the accuracy of our implementation by applying it to a large and diverse test set comprising 153 singlet excitations in organic molecules. Already moderate PNO thresholds yield mean absolute errors below 0.01 eV. The performance of the implementation is investigated through the calculations on alkene chains and reveals an at most cubic cost-scaling for the CCSD iterations with the system size.
International Nuclear Information System (INIS)
Ma, Yufei; Ji, Yuan; Huang, Guoyou; Zhang, Xiaohui; Xu, Feng; Ling, Kai
2015-01-01
Periodontitis is an inflammatory disease negatively affecting up to 15% of adults worldwide. Periodontal ligament stem cells (PDLSCs) hold great promises for periodontal tissue regeneration, where it is necessary to find proper extracellular matrix (ECM) materials (e.g., composition, concentration). In this study, we proposed a bioprinting-based approach to generate nano-liter sized three-dimensional (3D) cell-laden hydrogel array with gradient of ECM components, through controlling the volume ratio of two hydrogels, such as gelatin methacrylate (GelMA) and poly(ethylene glycol) (PEG) dimethacrylate. The resulting cell-laden array with a gradient of GelMA/PEG composition was used to screen human PDLSC response to ECM. The behavior (e.g., cell viability, spreading) of human PDLSCs in GelMA/PEG array were found to be depended on the volume ratios of GelMA/PEG, with cell viability and spreading area decreased along with increasing the ratio of PEG. The developed approach would be useful for screening cell-biomaterial interaction in 3D and promoting regeneration of functional tissue. (paper)
Heppner, K. J.; Matrisian, L. M.; Jensen, R. A.; Rodgers, W. H.
1996-01-01
Matrix metalloproteinase (MMP) family members have been associated with advanced-stage cancer and contribute to tumor progression, invasion, and metastasis as determined by inhibitor studies. In situ hybridization was performed to analyze the expression and localization of all known MMPs in a series of human breast cancer biopsy specimens. Most MMPs were localized to tumor stroma, and all MMPs had very distinct expression patterns. Matrilysin was expressed by morphologically normal epithelial ducts within tumors and in tissue from reduction mammoplasties, and by epithelial-derived tumor cells. Many family members, including stromelysin-3, gelatinase A, MT-MMP, interstitial collagenase, and stromelysin-1 were localized to fibroblasts of tumor stroma of invasive cancers but in quite distinct, and generally widespread, patterns. Gelatinase B, collagenase-3, and metalloelastase expression were more focal; gelatinase B was primarily localized to endothelial cells, collagenase-3 to isolated tumor cells, and metalloelastase to cytokeratin-negative, macrophage-like cells. The MMP inhibitor, TIMP-1, was expressed in both stromal and tumor components in most tumors, and neither stromelysin-2 nor neutrophil collagenase were detected in any of the tumors. These results indicate that there is very tight and complex regulation in the expression of MMP family members in breast cancer that generally represents a host response to the tumor and emphasize the need to further evaluate differential functions for MMP family members in breast tumor progression. Images Figure 1 Figure 2 Figure 3 PMID:8686751
In this study, we describe and evaluate the performance of a simple and rapid mass spectral method for screening fish plasma for estrogen-responsive biomarkers using matrix assisted laster desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) couopled with a short...
Singh, Satyendra K; Prasad, Kashi N; Singh, Aloukick K; Gupta, Kamlesh K; Singh, Amrita; Tripathi, Mukesh; Gupta, Rakesh K
2017-11-01
The treatment of neurocysticercosis (NCC) varies with location, number and stage of the Taenia solium cysticerci (cysts). Albendazole (ABZ) effectively kills cysticerci, and subsequently induces neuro-inflammation facilitated by leukocyte infiltration. We hypothesize that immune response varies around drug responder (degenerating/dying) and non-responder (viable) cysts after ABZ and ABZ plus steroid (ABZS) therapy, which may determine the disease pathogenesis. Twenty cysticercotic swine were treated with ABZ (n = 10; group1) and ABZS (n = 10; group2). Expression of adhesion molecules, chemokines and matrix metallo-proteinases (MMPs) was measured by qRT-PCR (quantitative reverse transcriptase-polymerase chain reaction) and ELISA. Gelatin gel zymography was performed to detect the activity of MMP-2 and -9. In group1, ABZ therapy induced higher expressions of ICAM-1 (intercellular adhesion molecule-1), VCAM-1 (vascular cell adhesion molecule-1), E-selectin, MCP-1 (monocyte chemotactic protein-1), Eotaxin-1, MIP-1α (macrophage inflammatory protein-1α), RANTES (regulated on activation, normal T cell expressed and secreted), MMP-2 and MMP-9 around ABZ responder (AR) cysts. Three pigs with cyst burdens ≥10 died following ABZ therapy. However, in group2, moderate expressions of ICAM-1, VCAM-1, E-selectin, RANTES and MMP-9 were associated with ABZS responder (ASR), whereas low expressions of these molecules were associated with ABZS non-responder (ASNR) cysts. In conclusion, ABZ alone therapy is not safe since it causes death of pigs due to higher inflammatory immune response around dying cysts. However, combination therapy is an effective treatment regimen even with the high cyst burden. Copyright © 2017 Elsevier Inc. All rights reserved.
Karaaslan, Y.; Gisi, B.; Sakiroglu, S.; Kasapoglu, E.; Sari, H.; Sokmen, I.
2018-02-01
We study the influence of electric field on the electronic energy band structure, zero-temperature ballistic conductivity and optical properties of double quantum wire. System described by double-well anharmonic confinement potential is exposed to a perpendicular magnetic field and Rashba and Dresselhaus spin-orbit interactions. Numerical results show up that the combined effects of internal and external agents cause the formation of crossing, anticrossing, camel-back/anomaly structures and the lateral, downward/upward shifts in the energy dispersion. The anomalies in the energy subbands give rise to the oscillation patterns in the ballistic conductance, and the energy shifts bring about the shift in the peak positions of optical absorption coefficients and refractive index changes.
National Aeronautics and Space Administration — Arabidopsis thaliana was evaluated for its response to the spaceflight environment in three replicated experiments on the International Space Station. Two approaches...
Spin-orbit scattering in superconducting nanoparticles
Energy Technology Data Exchange (ETDEWEB)
Alhassid, Y. [Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, Connecticut, 06520 (United States); Nesterov, K.N. [Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin, 53706 (United States)
2017-06-15
We review interaction effects in chaotic metallic nanoparticles. Their single-particle Hamiltonian is described by the proper random-matrix ensemble while the dominant interaction terms are invariants under a change of the single-particle basis. In the absence of spin-orbit scattering, the nontrivial invariants consist of a pairing interaction, which leads to superconductivity in the bulk, and a ferromagnetic exchange interaction. Spin-orbit scattering breaks spin-rotation invariance and when it is sufficiently strong, the only dominant nontrivial interaction is the pairing interaction. We discuss how the magnetic response of discrete energy levels of the nanoparticle (which can be measured in single-electron tunneling spectroscopy experiments) is affected by such pairing correlations and how it can provide a signature of pairing correlations. We also consider the spin susceptibility of the nanoparticle and discuss how spin-orbit scattering changes the signatures of pairing correlations in this observable. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Chao Yu Chiu
2001-01-01
The LHC injection transfer lines TI 2 and TI 8 will transport intense high-energy beams over considerable distances. In their regular part a FODO lattice is used with 4 bending magnets per half-cell and a half-cell length of 30.3 m, similar to that of the SPS. The relatively tight apertures in these lines require precise trajectory control. Following an earlier study a baseline correction scheme was chosen where two out of every four consecutive quadrupoles are complemented with correctors and beam position monitors ("2-in-4"). With the ordering of the equipment approaching, a further in-depth investigation has been made using a newly developed analytic method. This method evaluates, based on the design specifications, the global performance of an orbit correction system in terms of observability, correctability, correction range and response singularity. In addition, orbit and error envelopes are obtained over the full beam line in an efficient and rigorous manner, providing insights not easily accessible wi...
Ashley, G. M.
2001-12-01
Wet-dry cycles in low latitudes are generally attributed to changes in solar radiation related to the 21 kyr tempo of orbital precession. Stronger insolation drives stronger summer monsoon maxima that increase precipitation and in closed basins produce larger lakes. However, a Plio-Pleistocene record from a closed rift-platform basin near the equator suggests that the obliquity (41 kyr) signal is also present. The 1.85-1.75 Ma sedimentary record deposited in the Olduvai basin, 3oN, reveals clear evidence of periodic expansion and contraction of paleolake Olduvai. The closed basin was 50 km wide and infilled by volcaniclastic material from Ngorongoro volcanic complex in several depositional environments.. A saline-alkaline lake expanded up to 15 km in width and deposited Mg-smectitic claystones. The lake clays in the central basin vary in clay mineralogy and the number of calcite crystal horizons reflecting compositional changes in the lake water. Lake expansions are recorded at the margins where lake clays are intercollated with deltaic and ephemeral fluvial sands and with lake margin wetland deposits. Marine dust records, off both west and east Africa, suggest that the precession signal (21kyr) dominated the climate until 2.8 Ma and the obliquity signal (41kyr) from 2.8 to 0.9 Ma (deMenocal, 1995). In contrast, the stratigraphic sequence for playa lake expansion at Olduvai, that is constrained by the tephra chronology (1.85-1.75 Ma) and paleomagnetic record, documents the combined effects of both obliquity and precession cycles.
Lee, Yujung; Kwon, Jeongil; Khang, Gilson; Lee, Dongwon
2012-01-01
Vanillin is one of the major components of vanilla, a commonly used flavoring agent and preservative and is known to exert potent antioxidant and anti-inflammatory activities. In this work, vanillin-incorporated poly(lactic-co-glycolic acid) (PLGA) films and scaffolds were fabricated to evaluate the effects of vanillin on the inflammatory responses and extracellular matrix (ECM) formation in vitro and in vivo. The incorporation of vanillin to PLGA films induced hydrophilic nature, resulting i...
Zhang, Yunlin; Liu, Xiaohan; Osburn, Christopher L.; Wang, Mingzhu; Qin, Boqiang; Zhou, Yongqiang
2013-01-01
CDOM biogeochemical cycle is driven by several physical and biological processes such as river input, biogeneration and photobleaching that act as primary sinks and sources of CDOM. Watershed-derived allochthonous (WDA) and phytoplankton-derived autochthonous (PDA) CDOM were exposed to 9 days of natural solar radiation to assess the photobleaching response of different CDOM sources, using absorption and fluorescence (excitation-emission matrix) spectroscopy. Our results showed a marked decrea...
Franklin, Joel N
2003-01-01
Mathematically rigorous introduction covers vector and matrix norms, the condition-number of a matrix, positive and irreducible matrices, much more. Only elementary algebra and calculus required. Includes problem-solving exercises. 1968 edition.
International Nuclear Information System (INIS)
Michelotti, L.
1995-01-01
The past fifteen years have witnessed a remarkable development of methods for analyzing single particle orbit dynamics in accelerators. Unlike their more classic counterparts, which act upon differential equations, these methods proceed by manipulating Poincare maps directly. This attribute makes them well matched for studying accelerators whose physics is most naturally modelled in terms of maps, an observation that has been championed most vigorously by Forest. In the following sections the author sketchs a little background, explains some of the physics underlying these techniques, and discusses the best computing strategy for implementing them in conjunction with modeling accelerators
Bergshoeff, Eric A; Riccioni, Fabio
2012-01-01
We complete the classification of half-supersymmetric branes in toroidally compactified IIA/IIB string theory in terms of representations of the T-duality group. As a by-product we derive a last wrapping rule for the space-filling branes. We find examples of T-duality representations of branes in lower dimensions, suggested by supergravity, of which none of the component branes follow from the reduction of any brane in ten-dimensional IIA/IIB string theory. We discuss the constraints on the charges of half-supersymmetric branes, determining the corresponding T-duality and U-duality orbits.
Energy Technology Data Exchange (ETDEWEB)
Michelotti, L.
1995-01-01
The past fifteen years have witnessed a remarkable development of methods for analyzing single particle orbit dynamics in accelerators. Unlike their more classic counterparts, which act upon differential equations, these methods proceed by manipulating Poincare maps directly. This attribute makes them well matched for studying accelerators whose physics is most naturally modelled in terms of maps, an observation that has been championed most vigorously by Forest. In the following sections the author sketchs a little background, explains some of the physics underlying these techniques, and discusses the best computing strategy for implementing them in conjunction with modeling accelerators.
Directory of Open Access Journals (Sweden)
José Geraldo de Abreu Sousa Junior
2008-04-01
Full Text Available Parte da variabilidade dos índices de produção agrícola está associada com as características do solo e da paisagem. Dessa forma, práticas de manejo, como a adubação, devem levar em consideração esta variabilidade. O sensoriamento remoto é uma ferramenta que pode fornecer, de maneira rápida, informações para o manejo do solo, pois relaciona a radiação eletromagnética com os atributos do solo. Assim, este trabalho teve como objetivo avaliar o comportamento espectral, em dois níveis de aquisição de dados (terrestre e orbital, de diferentes classes de solos ao longo de toposseqüências na região de São Carlos e Ibaté, SP. Para isso, amostras de terra georreferenciadas foram coletadas em 319 pontos, em três profundidades. Em seguida, obtiveram-se os dados radiométricos em laboratório, na faixa espectral entre 450 e 2.500 nm. Os mesmos locais amostrados na camada superficial, no campo, foram avaliados na imagem de satélite. A partir dos resultados obtidos, pode-se concluir que: (a teores de areia grossa, argila e matéria orgânica, e cor tiveram relação com a reflectância dos solos; (b ao longo das vertentes ocorrem variações nos dados espectrais dos solos; e (c solos da mesma ordem taxonômica, porém com classes texturais diferentes, apresentam diferentes comportamentos espectrais, podendo ser discriminados por sensoriamento remoto.Part of agricultural production index variability is associated with soil and landscape characteristics. Management practices such as fertilizer application should therefore take the soil spatial variability into account. Remote sensing is a tool that can provide faster information for soil management because it relates electromagnetic radiation with soil attributes. Thus, this study aimed at evaluating the spectral response, at two data acquisition levels (terrestrial and orbital, of different soil classes across toposequences in the region of São Carlos and Ibaté, SP. For this
Hartree--Fock density matrix equation
International Nuclear Information System (INIS)
Cohen, L.; Frishberg, C.
1976-01-01
An equation for the Hartree--Fock density matrix is discussed and the possibility of solving this equation directly for the density matrix instead of solving the Hartree--Fock equation for orbitals is considered. Toward that end the density matrix is expanded in a finite basis to obtain the matrix representative equation. The closed shell case is considered. Two numerical schemes are developed and applied to a number of examples. One example is given where the standard orbital method does not converge while the method presented here does
Rhoades, Elizabeth R; Geisel, Rachel E; Butcher, Barbara A; McDonough, Sean; Russell, David G
2005-05-01
The chronic inflammatory response to Mycobacterium generates complex granulomatous lesions that balance containment with destruction of infected tissues. To study the contributing factors from host and pathogen, we developed a model wherein defined mycobacterial components and leukocytes are delivered in a gel, eliciting a localized response that can be retrieved and analysed. We validated the model by comparing responses to the cell wall lipids from Mycobacterium bovis bacillus Calmette-Guerin (BCG) to reported activities in other models. BCG lipid-coated beads and bone marrow-derived macrophages (input macrophages) were injected intraperitoneally into BALB/c mice. Input macrophages and recruited peritoneal exudate cells took up fluorescently tagged BCG lipids, and matrix-associated macrophages and neutrophils produced tumor necrosis factor, interleukin-1alpha, and interleukin-6. Leukocyte numbers and cytokine levels were greater in BCG lipid-bearing matrices than matrices containing non-coated or phosphatidylglycerol-coated beads. Leukocytes arrived in successive waves of neutrophils, macrophages and eosinophils, followed by NK and T cells (CD4(+), CD8(+), or gammadelta) at 7 days and B cells within 12 days. BCG lipids also predisposed matrices for adherence and vascularization, enhancing cellular recruitment. We submit that the matrix model presents pertinent features of the murine granulomatous response that will prove to be an adaptable method for study of this complex response.
Closed orbit feedback with digital signal processing
International Nuclear Information System (INIS)
Chung, Y.; Kirchman, J.; Lenkszus, F.
1994-01-01
The closed orbit feedback experiment conducted on the SPEAR using the singular value decomposition (SVD) technique and digital signal processing (DSP) is presented. The beam response matrix, defined as beam motion at beam position monitor (BPM) locations per unit kick by corrector magnets, was measured and then analyzed using SVD. Ten BPMs, sixteen correctors, and the eight largest SVD eigenvalues were used for closed orbit correction. The maximum sampling frequency for the closed loop feedback was measured at 37 Hz. Using the proportional and integral (PI) control algorithm with the gains Kp = 3 and K I = 0.05 and the open-loop bandwidth corresponding to 1% of the sampling frequency, a correction bandwidth (-3 dB) of approximately 0.8 Hz was achieved. Time domain measurements showed that the response time of the closed loop feedback system for 1/e decay was approximately 0.25 second. This result implies ∼ 100 Hz correction bandwidth for the planned beam position feedback system for the Advanced Photon Source storage ring with the projected 4-kHz sampling frequency
Bose, Anirbandeep; Wong, Tin Wui; Singh, Navjot
2013-04-01
The objective of this present investigation was to develop and formulate sustained release (SR) matrix tablets of Itopride HCl, by using different polymer combinations and fillers, to optimize by Central Composite Design response surface methodology for different drug release variables and to evaluate drug release pattern of the optimized product. Sustained release matrix tablets of various combinations were prepared with cellulose-based polymers: hydroxy propyl methyl cellulose (HPMC) and polyvinyl pyrolidine (pvp) and lactose as fillers. Study of pre-compression and post-compression parameters facilitated the screening of a formulation with best characteristics that underwent here optimization study by response surface methodology (Central Composite Design). The optimized tablet was further subjected to scanning electron microscopy to reveal its release pattern. The in vitro study revealed that combining of HPMC K100M (24.65 MG) with pvp(20 mg)and use of LACTOSE as filler sustained the action more than 12 h. The developed sustained release matrix tablet of improved efficacy can perform therapeutically better than a conventional tablet.
Grimes, D Jay; Ford, Tim E; Colwell, Rita R; Baker-Austin, Craig; Martinez-Urtaza, Jaime; Subramaniam, Ajit; Capone, Douglas G
2014-04-01
Satellite-based remote sensing of marine microorganisms has become a useful tool in predicting human health risks associated with these microscopic targets. Early applications were focused on harmful algal blooms, but more recently methods have been developed to interrogate the ocean for bacteria. As satellite-based sensors have become more sophisticated and our ability to interpret information derived from these sensors has advanced, we have progressed from merely making fascinating pictures from space to developing process models with predictive capability. Our understanding of the role of marine microorganisms in primary production and global elemental cycles has been vastly improved as has our ability to use the combination of remote sensing data and models to provide early warning systems for disease outbreaks. This manuscript will discuss current approaches to monitoring cyanobacteria and vibrios, their activity and response to environmental drivers, and will also suggest future directions.
LENUS (Irish Health Repository)
Moran, Ellen M
2009-01-01
INTRODUCTION: The aim of this study was to examine IL-17A in patients, following anti-TNF-alpha therapy and the effect of IL-17A on matrix turnover and cartilage degradation. METHODS: IL-17A expression was examined by ELISA and immunohistology in the rheumatoid arthritis (RA) joints. RA whole synovial tissue explant (RA ST), primary synovial fibroblasts (RASFC), human cartilage and chondrocyte cultures were stimulated with IL-17A +\\/- TNF-alpha and Oncostatin M (OSM). Matrix metalloproteinase (MMP) and tissue inhibitor (TIMP-1) were assessed by ELISA and zymography. Cartilage proteoglycan release was assessed histologically by Safranin-O staining. Clinical parameters, IL-17A, MMP\\/TIMP were assessed in patients pre\\/post biologic therapy. RESULTS: IL-17A levels were higher in RA vs osteoarthritis (OA)\\/normal joints (P < 0.05). IL-17A up-regulated MMP-1, -2, -9, and -13 in RA ST, RASFC, cartilage and chondrocyte cultures (P < 0.05). In combination with TNF-alpha and OSM, IL-17A shifted the MMP:TIMP-1 ratio in favor of matrix degradation (all P < 0.05). Cartilage proteoglycan depletion in response to IL-17A was mild; however, in combination with TNF-alpha or OSM showed almost complete proteoglycan depletion. Serum IL-17A was detected in 28% of patients commencing biologic therapy. IL-17A negative patients demonstrated reductions post therapy in serum MMP1\\/TIMP4, MMP3\\/TIMP1 and MMP3\\/TIMP4 ratios and an increase in CS846 (all P < 0.05). No significant changes were observed in IL-17A positive patients. CONCLUSIONS: IL-17A is produced locally in the inflamed RA joint. IL-17A promotes matrix turnover and cartilage destruction, especially in the presence of other cytokines, mimicking the joint environment. IL-17A levels are modulated in vivo, following anti-TNF therapy, and may reflect changes in matrix turnover.
Theory and design methods of special space orbits
Zhang, Yasheng; Zhou, Haijun
2017-01-01
This book focuses on the theory and design of special space orbits. Offering a systematic and detailed introduction to the hovering orbit, spiral cruising orbit, multi-target rendezvous orbit, initiative approaching orbit, responsive orbit and earth pole-sitter orbit, it also discusses the concept, theory, design methods and application of special space orbits, particularly the design and control method based on kinematics and astrodynamics. In addition the book presents the latest research and its application in space missions. It is intended for researchers, engineers and postgraduates, especially those working in the fields of orbit design and control, as well as space-mission planning and research.
Marinković, Aleksandar; Mih, Justin D.; Park, Jin-Ah; Liu, Fei
2012-01-01
Lung fibroblast functions such as matrix remodeling and activation of latent transforming growth factor-β1 (TGF-β1) are associated with expression of the myofibroblast phenotype and are directly linked to fibroblast capacity to generate force and deform the extracellular matrix. However, the study of fibroblast force-generating capacities through methods such as traction force microscopy is hindered by low throughput and time-consuming procedures. In this study, we improved at the detail level methods for higher-throughput traction measurements on polyacrylamide hydrogels using gel-surface-bound fluorescent beads to permit autofocusing and automated displacement mapping, and transduction of fibroblasts with a fluorescent label to streamline cell boundary identification. Together these advances substantially improve the throughput of traction microscopy and allow us to efficiently compute the forces exerted by lung fibroblasts on substrates spanning the stiffness range present in normal and fibrotic lung tissue. Our results reveal that lung fibroblasts dramatically alter the forces they transmit to the extracellular matrix as its stiffness changes, with very low forces generated on matrices as compliant as normal lung tissue. Moreover, exogenous TGF-β1 selectively accentuates tractions on stiff matrices, mimicking fibrotic lung, but not on physiological stiffness matrices, despite equivalent changes in Smad2/3 activation. Taken together, these results demonstrate a pivotal role for matrix mechanical properties in regulating baseline and TGF-β1-stimulated contraction of lung fibroblasts and suggest that stiff fibrotic lung tissue may promote myofibroblast activation through contractility-driven events, whereas normal lung tissue compliance may protect against such feedback amplification of fibroblast activation. PMID:22659883
Dang, Yiping; Li, Wei; Tran, Victoria; Khalil, Raouf A.
2013-01-01
Pregnancy is associated with uteroplacental and vascular remodeling in order to adapt for the growing fetus and the hemodynamic changes in the maternal circulation. We have previously shown upregulation of uterine matrix metalloproteinases (MMPs) during pregnancy. Whether pregnancy-associated changes in MMPs are localized to the uterus or are generalized in feto-placental and maternal circulation is unclear. Also, the mechanisms causing the changes in uteroplacental and vascular MMPs during p...
Herhaus, Peter; Habringer, Stefan; Vag, Tibor; Steiger, Katja; Slotta-Huspenina, Julia; Gerngroß, Carlos; Wiestler, Benedikt; Wester, Hans-Jürgen; Schwaiger, Markus; Keller, Ulrich
2017-12-01
CXCR4 belongs to the family of chemokine receptors. Together with its sole known ligand CXCL12 (SDF-1alpha), it has a pivotal role during organogenesis and for homing of hematopoietic stem cells. CXCR4 is overexpressed in various malignancies, and this is often associated with poor prognosis. Therefore, molecular imaging of CXCR4 bears a great potential for diagnostics and selecting patients for CXCR4-directed therapies. The CXCR4-directed positron emission tomography (PET) tracer [ 68 Ga]Pentixafor has been shown to visualize CXCR4 expression in various malignancies in vivo. Whereas this tracer has limitations compared to 18 F-Fluorodeoxyglucose ([ 18 F]FDG) in diagnostic PET imaging in peripheral tumour lesions, it might add valuable information in routine diagnostics and response assessment of tumours in close proximity to the central nervous system (CNS) and malignancies within this organ. As a proof-of-concept, we performed [ 68 Ga]Pentixafor PET imaging in a patient with extranodal marginal zone lymphoma (MZL) of the orbital cavities at diagnosis and for post-therapy response assessment. Compared to routinely conducted [ 18 F]FDG PET, the lymphoma lesions determined by magnetic resonance imaging (MRI) showed high tracer accumulation at diagnosis, which decreased upon treatment. We therefore propose that imaging of CXCR4 with [ 68 Ga]Pentixafor is a potential diagnostic tool for tumours close to or within the CNS and suggest this being studied in clinical trials.
Directory of Open Access Journals (Sweden)
O. Saka
1998-05-01
Full Text Available Fluxgate magnetometer data recorded at the dip-equator (Huancayo, Peru; 1.44°N, 355.9° in geomagnetic coordinates; 12.1°S, 75.2°W in geographic coordinates; L = 1.00 with higher accuracy of timing (0.1 s and amplitude resolution (0.01 nT were utilized to survey an onset of Pi 2 pulsations in the midnight sector (2100–0100 LT during PROMIS (Polar Region and Outer Magnetosphere International Study periods (1 March–20 June, 1986. It is found that changing field line magnitude and vector as observed by magnetometer on board the synchronous satellites in the midnight sector often takes place simultaneously with the onset of Pi 2 pulsations at the dip-equator. The field disturbances that follow thereafter tend to last for some time both at the geosynchronous altitudes and the dip-equator. In this report, we examine the initial response of the field lines in space, and attempt to classify how the field line vector changed in the meridional plane. Key words. Magnetospheric physics · Magnetospheric configuration and dynamics · MHD waves and instabilities · Plasmasphere
Directory of Open Access Journals (Sweden)
O. Saka
Full Text Available Fluxgate magnetometer data recorded at the dip-equator (Huancayo, Peru; 1.44°N, 355.9° in geomagnetic coordinates; 12.1°S, 75.2°W in geographic coordinates; L = 1.00 with higher accuracy of timing (0.1 s and amplitude resolution (0.01 nT were utilized to survey an onset of Pi 2 pulsations in the midnight sector (2100–0100 LT during PROMIS (Polar Region and Outer Magnetosphere International Study periods (1 March–20 June, 1986. It is found that changing field line magnitude and vector as observed by magnetometer on board the synchronous satellites in the midnight sector often takes place simultaneously with the onset of Pi 2 pulsations at the dip-equator. The field disturbances that follow thereafter tend to last for some time both at the geosynchronous altitudes and the dip-equator. In this report, we examine the initial response of the field lines in space, and attempt to classify how the field line vector changed in the meridional plane.
Key words. Magnetospheric physics · Magnetospheric configuration and dynamics · MHD waves and instabilities · Plasmasphere
International Nuclear Information System (INIS)
Grant, C.R.
1981-01-01
It could take a considerable amount of memory and processing time to represent a reactor in its simulation by means of a diffusion code and considering areas in which nuclear and geometrical properties are invariant, such as reflector, water columns, etc. To avoid an explicit representation of these zones, a method employing a matrix was developed consisting in expressing the net currents of each group as a function of the total flux. Estimates are made for different geometries, introducing the PUMA difussion code of materials. Several tests made proved a very sound reliability of the results obtained in 2 and 5 groups. (author) [es
Computed tomography of orbital myositis
International Nuclear Information System (INIS)
Dresner, S.C.; Rothfus, W.E.; Slamovits, T.L.; Kennerdell, J.S.; Curtin, H.D.
1984-01-01
The computerized tomographic (CT) scans of 11 consecutive patients with orbital myositis were reviewed to better characterize the CT appearance of this condition. The findings in this series differed from those of previous reports in several ways. Multiple muscle involvement predominated. Bilateral involvement was more frequent than previously reported. Enlargement of the tendon as well as the muscle was a frequent finding, but a normal tendinous insertion did not preclude the diagnosis of orbital myositis. Although the CT appearance of orbital myositis is often helpful, the findings are not pathognomonic; correlation with history, clinical findings, and therapeutic response must be considered in making the diagnosis
A simulation study of the global orbit feedback system for Pohang light source
International Nuclear Information System (INIS)
Kim, Kukhee; Shim, Kyuyeol; Cho, Moohyun; Namkung, Won; Ko, In Soo; Choi, Jinhyuk
2000-01-01
This paper describes the simulation of the global orbit feedback system using the singular value decomposition (SVD) method, the error minimization method, and the neural network method. Instead of facing unacceptable correction result raised occasionally in the SVD method, we choose the error minimization method for the global orbit feedback. This method provides minimum orbit errors while avoiding unacceptable corrections, and keeps the orbit within the dynamic aperture of the storage ring. We simulate the Pohang Light Source (PLS) storage ring using the Methodical Accelerator Design (MAD) code that generates the orbit distortions for the error minimization method and the learning data set for neural network method. In order to compare the effectiveness of the neural network method with others, a neural network is trained by the learning algorithm using the learning data set. The global response matrix with a minimum error and the trained neural network are used to the global orbit feedback system. The simulation shows that a selection of beam position monitors (BPMs) is very sensitive in the reduction of rms orbit distortions, and the random choice gives better results than any other cases. (author)
Prasetya, Nicholaus; Teck, Anastasia A; Ladewig, Bradley P
2018-02-13
The performance of two generation-3 light-responsive metal-organic framework (MOF), namely JUC-62 and PCN-250, was investigated in a mixed matrix membrane (MMM) form. Both of them were incorporated inside the matrimid as the polymer matrix. Using our custom-designed membrane testing cell, it was observed that the MMMs showed up to 9% difference in CO 2 permeability between its pristine and UV-irradiated condition. This shows that the light-responsive ability of the light-responsive MOFs could still be maintained. Thus, this finding is applicable in designing a smart material. Apart from that, the MMMs also has the potential to be applied for post-combustion carbon capture. At loadings up to 15 wt%, both CO 2 permeability and CO 2 /N 2 ideal selectivity could be significantly improved and surpassed the value exhibited by most of the MOF-matrimid MMM. Lastly the long term performance of the MMM was also evaluated and it was observed that both MMM could maintain their performance up to 1 month with only a slight decrease in CO 2 permeability observed for 10 wt% PCN-250-matrimid. This study then opens up the possibility to fabricate a novel anti-aging multifunctional membrane material that is applicable as a smart material and also in post combustion carbon capture applications.
Directory of Open Access Journals (Sweden)
Weigelt C.
2012-08-01
Full Text Available Two designs of square-celled metallic honeycomb structures fabricated by a modified extrusion technology based on a powder feedstock were investigated. The strength and ductility of these cellular materials are achieved by an austenitic CrNi (AISI 304 steel matrix particle reinforced by an MgO partially-stabilized zirconia building up their cell wall microstructure. Similar to the mechanical behaviour of the bulk materials, the strengthening mechanism and the martensitic phase transformations in the cell walls are affected by the deformation temperature and the nominal strain rate. The microstructure evolution during quasi-static and dynamic impact compression up to high strain rates of 103 1/s influences the buckling and failure behaviour of the honeycomb structures. In contrast to bending-dominated quasi-isotropic networks like open-celled metal foams, axial compressive loading to the honeycomb’s channels causes membrane stretching as well as crushing of the vertical cell node elements and cell walls. The presented honeycomb materials differ geometrically in their cell wall thickness-to-cell size-ratio. Therefore, the failure behaviour is predominantly controlled by global buckling and torsional-flexural buckling, respectively, accompanied by plastic matrix flow and strengthening of the cell wall microstructure.
Archer, A.W.; Maples, C.G.
1989-01-01
Numerous departures from ideal relationships are revealed by Monte Carlo simulations of widely accepted binomial coefficients. For example, simulations incorporating varying levels of matrix sparseness (presence of zeros indicating lack of data) and computation of expected values reveal that not only are all common coefficients influenced by zero data, but also that some coefficients do not discriminate between sparse or dense matrices (few zero data). Such coefficients computationally merge mutually shared and mutually absent information and do not exploit all the information incorporated within the standard 2 ?? 2 contingency table; therefore, the commonly used formulae for such coefficients are more complicated than the actual range of values produced. Other coefficients do differentiate between mutual presences and absences; however, a number of these coefficients do not demonstrate a linear relationship to matrix sparseness. Finally, simulations using nonrandom matrices with known degrees of row-by-row similarities signify that several coefficients either do not display a reasonable range of values or are nonlinear with respect to known relationships within the data. Analyses with nonrandom matrices yield clues as to the utility of certain coefficients for specific applications. For example, coefficients such as Jaccard, Dice, and Baroni-Urbani and Buser are useful if correction of sparseness is desired, whereas the Russell-Rao coefficient is useful when sparseness correction is not desired. ?? 1989 International Association for Mathematical Geology.
Neural networks and orbit control in accelerators
International Nuclear Information System (INIS)
Bozoki, E.; Friedman, A.
1994-01-01
An overview of the architecture, workings and training of Neural Networks is given. We stress the aspects which are important for the use of Neural Networks for orbit control in accelerators and storage rings, especially its ability to cope with the nonlinear behavior of the orbit response to 'kicks' and the slow drift in the orbit response during long-term operation. Results obtained for the two NSLS storage rings with several network architectures and various training methods for each architecture are given
Oktem, G; Vatansever, S; Ayla, S; Uysal, A; Aktas, S; Karabulut, B; Bilir, A
2006-02-01
Multicellular tumor spheroid (MTS) represents a three-dimensional structural form of tumors in laboratory conditions, and it has the characteristics of avascular micrometastases or intervascular spaces of big tumors. Recent studies indicate that extracellular matrix (ECM) proteins play a critical role in tumor metastasis, therefore normal and cancer cells require an ECM for survival, proliferation and differentiation. Doxorubicin and Docetaxel are widely used in the therapy of breast cancer, as well as in in vivo and in vitro studies. In this study, we examined the effect of apoptosis and proliferation of cells on the human breast cancer cell line, MCF-7, by using p53, bcl-2 and Ki67 gene expression, and the tendency to metastasis with extracellular matrix proteins, laminin and type IV collagen after chemotherapy in the spheroid model. The apoptotic cell death in situ was detected by TUNEL method. TUNEL-positive cells and positive immunoreactivities of laminin, type IV collagen, p53 and, bcl-2 were detected in the control group. There was no laminin and type IV collagen immunoreactivities in spheroids of drug groups. While TUNEL-positive cells and p53 immunoreactivity were detected in Docetaxel, Doxorubicin and Docetaxel/Doxorubicin groups, p53 immunoreactivity was not observed in the Docetaxel group. There was no bcl-2 immunoreactivity in either drug group. In addition, we did not detect Ki67 immunoreactivity in both control and drug treatment groups. However, the absence of Ki67 protein in MCF-7 breast multicellular tumor spheroids is possibly related to the cells in G0 or S phase. These chemotherapeutic agents may affect the presence of ECM proteins in this in vitro model of micrometastasis of spheroids. These findings suggest that the possible mechanism of cell death in Doxorubicin and Docetaxel/Doxorubicin treatment groups is related to apoptosis through the p53 pathway. However, we considered the possibility that there is another control mechanism for the
Rosengren, Mats
1991-12-01
The European remote sensing mission orbit control is addressed. For the commissioning phase, the orbit is defined by the following requirements: Sun synchronous, local time of descending node 10:30; three days repeat cycle with 43 orbital revolutions; overhead Venice tower (12.508206 deg east, 45.314222 deg north). The launch, maneuvers for the initial acquisition of the operational orbit, orbit maintenance maneuvers, evaluation of the orbit control, and the drift of the inclination are summarized.
International Nuclear Information System (INIS)
Lydia, Emilio J.; Barros, Ricardo C.
2011-01-01
In this paper we describe a response matrix method for one-speed slab-geometry discrete ordinates (SN) neutral particle transport problems that is completely free from spatial truncation errors. The unknowns in the method are the cell-edge angular fluxes of particles. The numerical results generated for these quantities are exactly those obtained from the analytic solution of the SN problem apart from finite arithmetic considerations. Our method is based on a spectral analysis that we perform in the SN equations with scattering inside a discretization cell of the spatial grid set up on the slab. As a result of this spectral analysis, we are able to obtain an expression for the local general solution of the SN equations. With this local general solution, we determine the response matrix and use the prescribed boundary conditions and continuity conditions to sweep across the discretization cells from left to right and from right to left across the slab, until a prescribed convergence criterion is satisfied. (author)
Kasesaz, Y; Khalafi, H; Rahmani, F
2013-12-01
Optimization of the Beam Shaping Assembly (BSA) has been performed using the MCNP4C Monte Carlo code to shape the 2.45 MeV neutrons that are produced in the D-D neutron generator. Optimal design of the BSA has been chosen by considering in-air figures of merit (FOM) which consists of 70 cm Fluental as a moderator, 30 cm Pb as a reflector, 2mm (6)Li as a thermal neutron filter and 2mm Pb as a gamma filter. The neutron beam can be evaluated by in-phantom parameters, from which therapeutic gain can be derived. Direct evaluation of both set of FOMs (in-air and in-phantom) is very time consuming. In this paper a Response Matrix (RM) method has been suggested to reduce the computing time. This method is based on considering the neutron spectrum at the beam exit and calculating contribution of various dose components in phantom to calculate the Response Matrix. Results show good agreement between direct calculation and the RM method. Copyright © 2013 Elsevier Ltd. All rights reserved.
Application of the RT-0 nodal methods and NRMPO matrix-response to the cycles 1 and 2 of the LVC
International Nuclear Information System (INIS)
Delfin L, A.; Hernandez L, H.; Alonso V, G.
2005-01-01
The nodal methods the same as that of matrix-response are used to develop numeric calculations, so much in static as dynamics of reactors, in one, two and three dimensions. The topic of this work is to apply the equations modeled in the RPM0 program, obtained when using the nodal scheme RT-0 (Raviart-Thomas index zero) in the neutron diffusion equation in stationary state X Y geometry, applying finite differences centered in mesh and lineal reactivity; also, to use those equations captured in the NRMPO program developed by E. Malambu that uses the matrix-response method in X Y geometry. The numeric results of the radial distribution of power by fuel assembly of the unit 1, in the cycles 1 and 2 of the CLV obtained by both methods, they are compared with the calculations obtained with the CM-PRESTO code that is a neutronic-thermo hydraulic simulator in three dimensions. The comparison of the radial distribution of power in the cycles 1 and 2 of the CLV with the CM-PRESTO code, it presents for RPM0 maximum errors of 8.2% and 12.4% and for NRMPO 31.2% and 61.3% respectively. The results show that it can be feasible to use the program RPM0 like a quick and efficient tool in the multicycle analysis in the fuel management. (Author)
DEFF Research Database (Denmark)
Yoneda, Atsuko; Morgan-Fisher, Marie; Wait, Robin
2012-01-01
Collapsin response mediator protein 2 (CRMP-2) is known as a regulator of neuronal polarity and differentiation through microtubule assembly and trafficking. Here, we show that CRMP-2 is ubiquitously expressed and a splice variant (CRMP-2L), which is expressed mainly in epithelial cells among...... nonneuronal cells, regulates myosin II-mediated cellular functions, including cell migration. While the CRMP-2 short form (CRMP-2S) is recognized as a substrate of the Rho-GTP downstream kinase ROCK in neuronal cells, a CRMP-2 complex containing 2L not only bound the catalytic domain of ROCK II through two......-2L but not -2S inhibited fibronectin matrix assembly in fibroblasts. Underlying these responses, CRMP-2L regulated the kinase activity of ROCK II but not ROCK I, independent of GTP-RhoA levels. This study provides a new insight into CRMP-2 as a controller of myosin II-mediated cellular functions...
Bodewig, E
1959-01-01
Matrix Calculus, Second Revised and Enlarged Edition focuses on systematic calculation with the building blocks of a matrix and rows and columns, shunning the use of individual elements. The publication first offers information on vectors, matrices, further applications, measures of the magnitude of a matrix, and forms. The text then examines eigenvalues and exact solutions, including the characteristic equation, eigenrows, extremum properties of the eigenvalues, bounds for the eigenvalues, elementary divisors, and bounds for the determinant. The text ponders on approximate solutions, as well
Methods of orbit correction system optimization
International Nuclear Information System (INIS)
Chao, Yu-Chiu.
1997-01-01
Extracting optimal performance out of an orbit correction system is an important component of accelerator design and evaluation. The question of effectiveness vs. economy, however, is not always easily tractable. This is especially true in cases where betatron function magnitude and phase advance do not have smooth or periodic dependencies on the physical distance. In this report a program is presented using linear algebraic techniques to address this problem. A systematic recipe is given, supported with quantitative criteria, for arriving at an orbit correction system design with the optimal balance between performance and economy. The orbit referred to in this context can be generalized to include angle, path length, orbit effects on the optical transfer matrix, and simultaneous effects on multiple pass orbits
Evaluation of the synchrotron close orbit
International Nuclear Information System (INIS)
Bashmakov, Yu.A.; Karpov, V.A.
1991-01-01
The knowledge of the closed orbit position is an essential condition for the effective work of any accelerator. Therefore questions of calculations, measurements and controls have great importance. For example, during injection of particles into a synchrotron, the amplitudes of their betatron oscillations may become commensurable with the working region of the synchrotron. This makes one pay attention at the problem of formation of the optimum orbit with use of correcting optical elements. In addition, it is often necessary to calculate such an orbit at the end of the acceleration cycle when particles are deposited at internal targets or removed from the synchrotron. In this paper, the computation of the close orbit is reduced to a determination at an arbitrarily chosen azimuth of the eigenvector of the total transfer matrix of the synchrotron ring and to tracing with this vector desired orbit. The eigenvector is found as a result of an iteration
Susilo, Monica E; Roeder, Blayne A; Voytik-Harbin, Sherry L; Kokini, Klod; Nauman, Eric A
2010-04-01
The three-dimensional microstructure and mechanical properties of the collagen fibrils within the extracellular matrix (ECM) is now being recognized as a primary factor in regulating cell proliferation and differentiation. Therefore, an appreciation of the mechanical aspects by which a cell interacts with its ECM is required for the development of engineered tissues. Ultimately, using these interactions to design tissue equivalents requires mathematical models with three-dimensional architecture. In this study, a three-dimensional model of a collagen fibril matrix undergoing uniaxial tensile stress was developed by making use of cellular solids. A structure consisting of thin struts was chosen to represent the arrangement of collagen fibrils within an engineered ECM. To account for the large deformation of tissues, the collagen fibrils were modeled as hyperelastic neo-Hookean or Mooney-Rivlin materials. The use of cellular solids allowed the fibril properties to be related to the ECM properties in closed form, which, in turn, allowed the estimation of fibril properties using ECM experimental data. A set of previously obtained experimental data consisting of simultaneous measures of the fibril microstructure and mechanical tests was used to evaluate the model's capability to estimate collagen fibril mechanical property when given tissue-scale data and to predict the tissue-scale mechanical properties when given estimated fibril stiffness. The fibril tangent modulus was found to be 1.26 + or - 0.70 and 1.62 + or - 0.88 MPa when the fibril was modeled as neo-Hookean and Mooney-Rivlin material, respectively. There was no statistical significance of the estimated fibril tangent modulus among the different groups. Sensitivity analysis showed that the fibril mechanical properties and volume fraction were the two input parameters which required accurate values. While the volume fraction was easily obtained from the initial image of the gel, the fibril mechanical properties
Kurková, Dana; Judas, Libor
2018-05-01
Gamma and X-ray energy spectra measured with semiconductor detectors suffer from various distortions, one of them being so-called "tailing" caused by an incomplete charge collection. Using the Hecht equation, a response matrix of size 321 × 321 was constructed which was used to correct the effect of incomplete charge collection. The correction matrix was constructed analytically for an arbitrary energy bin and the size of the energy bin thus defines the width of the spectral window. The correction matrix can be applied separately from other possible spectral corrections or it can be incorporated into an already existing response matrix of the detector. The correction was tested and its adjustable parameters were optimized on the line spectra of 57Co measured with a cadmium telluride (CdTe) detector in a spectral range from 0 up to 160 keV. The best results were obtained when the values of the free path of holes were spread over a range from 0.4 to 1.0 cm and weighted by a Gauss function. The model with the optimized parameter values was then used to correct the line spectra of 152Eu in a spectral range from 0 up to 530 keV. An improvement in the energy resolution at full width at half maximum from 2.40 % ± 0.28 % to 0.96 % ± 0.28 % was achieved at 344.27 keV. Spectra of "narrow spectrum series" beams, N120, N150, N200, N250 and N300, generated with tube voltages of 120 kV, 150 kV, 200 kV, 250 kV and 300 kV respectively, and measured with the CdTe detector, were corrected in the spectral range from 0 to 160 keV (N120 and N150) and from 0 to 530 keV (N200, N250, N300). All the measured spectra correspond both qualitatively and quantitatively to the available reference data after the correction. To obtain better correspondence between N150, N200, N250 and N300 spectra and the reference data, lower values of the free paths of holes (range from 0.16 to 0.65 cm) were used for X-ray spectra correction, which suggests energy dependence of the phenomenon.
Energy Technology Data Exchange (ETDEWEB)
Rusen, L. [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, RO-077125 Magurele, Bucharest (Romania); Dinca, V., E-mail: dinali@nipne.ro [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, RO-077125 Magurele, Bucharest (Romania); Mitu, B. [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, RO-077125 Magurele, Bucharest (Romania); Mustaciosu, C. [Horia Hulubei National Institute of Physics and Nuclear Engineering, IFIN HH, Magurele, Bucharest (Romania); Dinescu, M. [NILPRP, National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, PO Box MG-16, RO-077125 Magurele, Bucharest (Romania)
2014-05-01
Multifunctional thin films used as thermoresponsive substrate for engineering cell sheets represent an important area in tissue engineering. As the morphology and the chemical characteristics of the thin films directly control their interaction with cells, it is important to correlate these characteristics with the biological answer. In this study, thermally sensitive poly(N-isopropylacrylamide), (pNIPAAm) thin films were prepared by matrix assisted pulsed laser evaporation and utilized in L929 cell adhesion and detachment studies. Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) were used to determine the pNIPAAm thin films chemical and morphological characteristics. The FTIR data demonstrated that the functional groups in the MAPLE-deposited films remained intact for fluences in the range of 200–600 mJ cm{sup −2}. Within this fluence range, the AFM topographical studies showed that the roughness of the coatings was dependent on laser fluence and the obtained surfaces were characterized by a granular aspect. L929 cell viability studies onto the pNIPAAm coatings showed little or no toxic effect for fluences below 600 mJ cm{sup −2}, while for higher fluences, viability was decreased with more than 50%. The adhesion and detachment of the cell was found to be mainly dependent on the film surface morphology.
Orbitals from local RDMFT: Are they Kohn-Sham or natural orbitals?
International Nuclear Information System (INIS)
Theophilou, Iris; Helbig, Nicole; Lathiotakis, Nektarios N.; Gidopoulos, Nikitas I.; Rubio, Angel
2015-01-01
Recently, an approximate theoretical framework was introduced, called local reduced density matrix functional theory (local-RDMFT), where functionals of the one-body reduced density matrix (1-RDM) are minimized under the additional condition that the optimal orbitals satisfy a single electron Schrödinger equation with a local potential. In the present work, we focus on the character of these optimal orbitals. In particular, we compare orbitals obtained by local-RDMFT with those obtained with the full minimization (without the extra condition) by contrasting them against the exact NOs and orbitals from a density functional calculation using the local density approximation (LDA). We find that the orbitals from local-RMDFT are very close to LDA orbitals, contrary to those of the full minimization that resemble the exact NOs. Since local RDMFT preserves the good quality of the description of strong static correlation, this finding opens the way to a mixed density/density matrix scheme, where Kohn-Sham orbitals obtain fractional occupations from a minimization of the occupation numbers using 1-RDM functionals. This will allow for a description of strong correlation at a cost only minimally higher than a density functional calculation
Grenfell, John Lee; Griessmeier, Jean-Mathias; Patzer, Beate; Rauer, Heike; Segura, Antigona; Stadelmann, Anja; Stracke, Barbara; Titz, Ruth; Von Paris, Philip
2007-02-01
Planets orbiting in the habitable zone of M dwarf stars are subject to high levels of galactic cosmic rays (GCRs), which produce nitrogen oxides (NOx) in Earth-like atmospheres. We investigate to what extent these NO(Mx) species may modify biomarker compounds such as ozone (O3) and nitrous oxide (N2O), as well as related compounds such as water (H2O) (essential for life) and methane (CH4) (which has both abiotic and biotic sources). Our model results suggest that such signals are robust, changing in the M star world atmospheric column due to GCR NOx effects by up to 20% compared to an M star run without GCR effects, and can therefore survive at least the effects of GCRs. We have not, however, investigated stellar cosmic rays here. CH4 levels are about 10 times higher on M star worlds than on Earth because of a lowering in hydroxyl (OH) in response to changes in the ultraviolet. The higher levels of CH4 are less than reported in previous studies. This difference arose partly because we used different biogenic input. For example, we employed 23% lower CH4 fluxes compared to those studies. Unlike on Earth, relatively modest changes in these fluxes can lead to larger changes in the concentrations of biomarker and related species on the M star world. We calculate a CH4 greenhouse heating effect of up to 4K. O3 photochemistry in terms of the smog mechanism and the catalytic loss cycles on the M star world differs considerably compared with that of Earth.
Chatterjee, A.; Schimel, D.; Stephens, B. B.; Crisp, D.; Eldering, A.; Gunson, M. R.; Feely, R. A.; Gierach, M. M.; Keeling, R. F.; Sutton, A. J.; Weir, B.
2017-12-01
The El Nino Southern Oscillation (ENSO) is the most important mode of tropical climate variability on interannual to decadal time scales. Correlations between atmospheric CO2 growth rate and ENSO activity are relatively well known but the magnitude of this correlation, the contribution from tropical marine vs. terrestrial flux components, and the causal mechanisms, are poorly constrained in space and time. The launch of NASA's Orbiting Carbon Observatory-2 (OCO-2) mission in July 2014 was rather timely given the development of strong ENSO conditions over the tropical Pacific Ocean in 2015-2016. In this presentation, we will discuss how the high-density observations from OCO-2 provided us with a novel dataset to resolve the linkages between El Niño and atmospheric CO2. Along with information from in situ observations of ΔpCO2 from NOAA's Tropical Atmosphere Ocean (TAO) project and atmospheric CO2 from the Scripps CO2 Program, and other remote-sensing missions, we are able to piece together the time dependent response of atmospheric CO2 concentrations over the Tropics. Our findings confirm the hypothesis from studies following the 1997-1998 El Niño event that an early reduction in CO2 outgassing from the tropical Pacific Ocean is later reversed by enhanced net CO2 emissions from the terrestrial biosphere. This implies that a component of the interannual variability (IAV) in the growth rate of atmospheric CO2, which has typically been used to constrain the climate sensitivity of tropical land carbon fluxes, is strongly influenced and modified by ocean fluxes during the early phase of the ENSO event. Our analyses shed further light on the understanding of the marine vs. terrestrial partitioning of tropical carbon fluxes during El Niño events, their relative contributions to the global atmospheric CO2 growth rate, and provide clues about the sensitivity of the carbon cycle to climate forcing on interannual time scales.
Smit, M.G.D.; Kater, B.J.; Jak, R.G.; Heuvel-Greve, van den M.J.
2006-01-01
Bioassays can be used for the assessment of sediment contamination. The response is classified based on a statistical scale indicating a certain effect percentage being significantly different from the controls (e.g. mortality classes of 0¿10%, 10¿20% etc.). The ecological relevance of this
International Nuclear Information System (INIS)
Ozeki, Nobuaki; Hase, Naoko; Kawai, Rie; Yamaguchi, Hideyuki; Hiyama, Taiki; Kondo, Ayami; Nakata, Kazuhiko; Mogi, Makio
2015-01-01
A pro-inflammatory cytokine mixture (CM: interleukin (IL)-1β, tumor necrosis factor-α and interferon-γ) and IL-1β-induced matrix metalloproteinase (MMP)-3 activity have been shown to increase the proliferation of rat dental pulp cells and murine stem cell-derived odontoblast-like cells. This suggests that MMP-3 may regulate wound healing and regeneration in the odontoblast-rich dental pulp. Here, we determined whether these results can be extrapolated to human dental pulp by investigating the effects of CM-induced MMP-3 up-regulation on the proliferation and apoptosis of purified odontoblast-like cells derived from human skeletal muscle stem cells. We used siRNA to specifically reduce MMP-3 expression. We found that CM treatment increased MMP-3 mRNA and protein levels as well as MMP-3 activity. Cell proliferation was also markedly increased, with no changes in apoptosis, upon treatment with CM and following the application of exogenous MMP-3. Endogenous tissue inhibitors of metalloproteinases were constitutively expressed during all experiments and unaffected by MMP-3. Although treatment with MMP-3 siRNA suppressed cell proliferation, it also unexpectedly increased apoptosis. This siRNA-mediated increase in apoptosis could be reversed by exogenous MMP-3. These results demonstrate that cytokine-induced MMP-3 activity regulates cell proliferation and suppresses apoptosis in human odontoblast-like cells. - Highlights: • Pro-inflammatory cytokines induce MMP-3 activity in human odontoblast-like cells. • Increased MMP-3 activity can promote cell proliferation in odontoblasts. • Specific loss of MMP-3 increases apoptosis in odontoblasts. • MMP-3 has potential as a promising new target for pupal repair and regeneration
Naqvi, Syeda M; Buckley, Conor T
2015-12-01
Bone marrow (BM) stem cells may be an ideal source of cells for intervertebral disc (IVD) regeneration. However, the harsh biochemical microenvironment of the IVD may significantly influence the biological and metabolic vitality of injected stem cells and impair their repair potential. This study investigated the viability and production of key matrix proteins by nucleus pulposus (NP) and BM stem cells cultured in the typical biochemical microenvironment of the IVD consisting of altered oxygen and glucose concentrations. Culture-expanded NP cells and BM stem cells were encapsulated in 1.5% alginate and ionically crosslinked to form cylindrical hydrogel constructs. Hydrogel constructs were maintained under different glucose concentrations (1, 5 and 25 mM) and external oxygen concentrations (5 and 20%). Cell viability was measured using the Live/Dead® assay and the production of sulphated glycosaminoglycans (sGAG), and collagen was quantified biochemically and histologically. For BM stem cells, IVD-like micro-environmental conditions (5 mM glucose and 5% oxygen) increased the accumulation of sGAG and collagen. In contrast, low glucose conditions (1 mM glucose) combined with 5% external oxygen concentration promoted cell death, inhibiting proliferation and the accumulation of sGAG and collagen. NP-encapsulated alginate constructs were relatively insensitive to oxygen concentration or glucose condition in that they accumulated similar amounts of sGAG under all conditions. Under IVD-like microenvironmental conditions, NP cells were found to have a lower glucose consumption rate compared with BM cells and may in fact be more suitable to adapt and sustain the harsh microenvironmental conditions. Considering the highly specialised microenvironment of the central NP, these results indicate that IVD-like concentrations of low glucose and low oxygen are critical and influential for the survival and biological behaviour of stem cells. Such findings may promote and accelerate
Energy Technology Data Exchange (ETDEWEB)
Ozeki, Nobuaki; Hase, Naoko; Kawai, Rie; Yamaguchi, Hideyuki; Hiyama, Taiki [Department of Endodontics, School of Dentistry, Aichi Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya 464-8651, Aichi (Japan); Kondo, Ayami [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650 (Japan); Nakata, Kazuhiko [Department of Endodontics, School of Dentistry, Aichi Gakuin University, 2-11 Suemori-dori, Chikusa-ku, Nagoya 464-8651, Aichi (Japan); Mogi, Makio, E-mail: makio@dpc.agu.ac.jp [Department of Medicinal Biochemistry, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-ku, Nagoya 464-8650 (Japan)
2015-02-01
A pro-inflammatory cytokine mixture (CM: interleukin (IL)-1β, tumor necrosis factor-α and interferon-γ) and IL-1β-induced matrix metalloproteinase (MMP)-3 activity have been shown to increase the proliferation of rat dental pulp cells and murine stem cell-derived odontoblast-like cells. This suggests that MMP-3 may regulate wound healing and regeneration in the odontoblast-rich dental pulp. Here, we determined whether these results can be extrapolated to human dental pulp by investigating the effects of CM-induced MMP-3 up-regulation on the proliferation and apoptosis of purified odontoblast-like cells derived from human skeletal muscle stem cells. We used siRNA to specifically reduce MMP-3 expression. We found that CM treatment increased MMP-3 mRNA and protein levels as well as MMP-3 activity. Cell proliferation was also markedly increased, with no changes in apoptosis, upon treatment with CM and following the application of exogenous MMP-3. Endogenous tissue inhibitors of metalloproteinases were constitutively expressed during all experiments and unaffected by MMP-3. Although treatment with MMP-3 siRNA suppressed cell proliferation, it also unexpectedly increased apoptosis. This siRNA-mediated increase in apoptosis could be reversed by exogenous MMP-3. These results demonstrate that cytokine-induced MMP-3 activity regulates cell proliferation and suppresses apoptosis in human odontoblast-like cells. - Highlights: • Pro-inflammatory cytokines induce MMP-3 activity in human odontoblast-like cells. • Increased MMP-3 activity can promote cell proliferation in odontoblasts. • Specific loss of MMP-3 increases apoptosis in odontoblasts. • MMP-3 has potential as a promising new target for pupal repair and regeneration.
Dang, Yiping; Li, Wei; Tran, Victoria; Khalil, Raouf A
2013-09-15
Pregnancy is associated with uteroplacental and vascular remodeling in order to adapt for the growing fetus and the hemodynamic changes in the maternal circulation. We have previously shown upregulation of uterine matrix metalloproteinases (MMPs) during pregnancy. Whether pregnancy-associated changes in MMPs are localized to the uterus or are generalized in feto-placental and maternal circulation is unclear. Also, the mechanisms causing the changes in uteroplacental and vascular MMPs during pregnancy are unclear. MMPs expression, activity and tissue distribution were measured in uterus, placenta and aorta of virgin, mid-pregnant (mid-Preg) and late pregnant (late-Preg) rats. Western blots and gelatin zymography revealed increases in MMP-2 and -9 in uterus and aorta of late-Preg compared with virgin and mid-Preg rats. In contrast, MMP-2 and -9 were decreased in placenta of late-Preg versus mid-Preg rats. Extracellular MMP inducer (EMMPRIN) was increased in uterus and aorta of pregnant rats, but was less in placenta of late-Preg than mid-Preg rats. Prolonged treatment of uterus or aorta of virgin rats with 17β-estradiol and progesterone increased the amount of EMMPRIN, MMP-2 and -9, and the sex hormone-induced increases in MMPs were prevented by EMMPRIN neutralizing antibody. Immunohistochemistry revealed that MMP-2 and -9 and EMMPRIN increased in uterus and aorta of pregnant rats, but decreased in placenta of late-Preg versus mid-Preg rats. Thus pregnancy-associated upregulation of uterine MMPs is paralleled by increased vascular MMPs, and both are mediated by EMMPRIN and induced by estrogen and progesterone, suggesting similar role of MMPs in uterine and vascular tissue remodeling and function during pregnancy. The decreased MMPs and EMMPRIN in placenta of late-Preg rats suggests reduced role of MMPs in feto-placental circulation during late pregnancy. Copyright © 2013 Elsevier Inc. All rights reserved.
African Journals Online (AJOL)
was done without contrast and 3mm/5mm/10mm slices were obtained to cover the orbit, skull base and brain. The findings included a soft tissue mass arising from the orbit. The left eye ball was extra orbital. There was no defect .... love's Short Practice of Surgery. 7 Edition,. Levis London, 1997; 45-64. 2. Orbital tumor Part 1, ...
Complex molecular orbital method: open-shell theory
International Nuclear Information System (INIS)
Hendekovic, J.
1976-01-01
A singe-determinant open-shell formalism for complex molecular orbitals is developed. An iterative algorithm for solving the resulting secular equations is constructed. It is based on a sequence of similarity transformations and matrix triangularizations
International Nuclear Information System (INIS)
Abujamra, S.
1983-01-01
The authors present a method called ''Radiovolumetry of the orbit'' that permits the evaluation of the orbital volume from anteroposterior skull X-Rays (CALDWELL 30 0 position). The research was based in the determination of the orbital volume with lead spheres, in 1010 orbits of 505 dry skulls of Anatomy Museums. After the dry skulls was X-rayed six frontal orbital diameters were made, with care to correct the radiographic amplification. PEARSON correlation coeficient test was applied between the mean orbital diameter and the orbital volume. The result was r = 0,8 with P [pt
Global DC closed orbit correction experiments on the NSLS X-ray ring and SPEAR
International Nuclear Information System (INIS)
Chung, Y.; Decker, G.; Evans, K. Jr.; Safranek, J.; So, I.; Tang, Y.; Corbett, W.J.; Hettel, R.
1993-01-01
The global closed orbit correction experiments conducted on the NSLS X-ray ring and the SPEAR using the technique of singular value decomposition (SVD) are presented. The beam response matrix, defined as beam motion at beam position monitor (BPM) locations per unit kick by corrector magnets, was measured and then analyzed using SVD. The BPMs and correctors are reconfigured into open-quotes transformedclose quotes BPMs (t-BPMs) and open-quotes transformedclose quotes correctors (t-correctors), with each T-BPM coupled to at most one t-corrector and vice versa for orbit correction. The decoupled t-BPMs are used to estimate the limit on orbit correction, while the decoupled t-correctors are used to optimize the corrector strengths. As a result the vertical r.m.s. orbit error at the BPM locations was reduced from 208 μm to 61 μm about an arbitrary reference orbit in the NSLS X-ray ring. In SPEAR, the vertical closed orbit was brought to the BPM centers at the selected BPM locations with an r.m.s. error of 215 μm reduced from the initial 780 μm
Effect of an elliptical orbit on SPECT resolution and image uniformity
International Nuclear Information System (INIS)
Gottschalk, S.; Salem, D.
1982-01-01
This paper studies the impact of elliptical motion on SPECT resolution and detector flood correction as implemented in a Technicare Omega 500. Bringing the detector closer to the object improves detector resolution in each view, which results in improved resolution in the reconstructed image. In the Omega 500 the elliptical orbit is realized by a succession of translational and rotational motions of the detector head. This introduces motion of the detector center relative to the object center. Statistical fluctuations in the flood correction matrix due to the finite acquisition time result in ring artifacts for the circular orbit. The relative center motion of an elliptical orbit results in an averaging of the flood correction noise and a significant reduction in artifacts. These two aspects of SPECT spatial resolution and flood correction response improvement in elliptical orbit have been analyzed through computer simulations for point sources and a uniform activity 20 x 30 cm ellipse. Results compared a 35 cm diameter circular orbit to a 35 x 25 cm elliptical orbit
DEFF Research Database (Denmark)
González-Santamaría, José; Villalba, María; Busnadiego, Oscar
2016-01-01
arrhythmias, and sudden cardiac death. Cardiac fibrosis is characterized by extensive deposition of collagen and also by increased stiffness as a consequence of enhanced collagen cross-linking. Members of the lysyl oxidase (LOX) family of enzymes are responsible for the formation of collagen cross......-links. This study investigates the contribution of LOX family members to the heart response to MI. METHODS AND RESULTS: Experimental MI was induced in C57BL/6 mice by permanent ligation of the left anterior descending coronary artery. The expression of LOX isoforms (LOX and LOXL1-4) was strongly increased upon MI...... resulted in reduced ventricular dilatation and improved cardiac function. CONCLUSION: LOX family members contribute significantly to the detrimental effects of cardiac remodelling, highlighting LOX inhibition as a potential therapeutic strategy for post-infarction recovery....
Drew, Benjamin T; Smith, Toby O; Littlewood, Chris; Sturrock, Ben
2014-06-01
Previous reviews have highlighted the benefit of loaded therapeutic exercise in the treatment of tendinopathy. Changes in observable structural outcomes have been suggested as a possible explanation for this response to therapeutic exercise. However, the mechanism for the efficacy of therapeutic exercise remains unclear. To systematically review the relationship between the observable structural change and clinical outcomes following therapeutic exercise. An electronic search of AMED, CiNAHL, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PEDro and SPORTDiscus was undertaken from their inception to June 2012. Any study design that incorporated observable structural outcomes and clinical outcomes when assessing the effect of therapeutic exercise on participants with tendinopathy. Included studies were appraised for risk of bias using the tool developed by the Cochrane Back Review Group. Due to heterogeneity of studies, a qualitative synthesis was undertaken. Twenty articles describing 625 patients were included. Overall, there is a strong evidence to refute any observable structural change as an explanation for the response to therapeutic exercise when treated by eccentric exercise training. Moderate evidence does exist to support the response of heavy-slow resistance training (HSR). The available literature does not support observable structural change as an explanation for the response of therapeutic exercise except for some support from HSR. Future research should focus on indentifying other explanations including neural, biochemical and myogenic changes. Registered with PROSPERO, registration number CRD42011001638. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
International Nuclear Information System (INIS)
Alvarenga, M.A.B.
1980-12-01
An analytical procedure to solve the neutron diffusion equation in two dimensions and two energy groups was developed. The response matrix method was used coupled with an expansion of the neutron flux in finite Fourier series. A computer code 'MRF2D' was elaborated to implement the above mentioned procedure for PWR reactor core calculations. Different core symmetry options are allowed by the code, which is also flexible enough to allow for improvements by means of algorithm optimization. The code performance was compared with a corner mesh finite difference code named TVEDIM by using a International Atomic Energy Agency (IAEA) standard problem. Computer processing time 12,7% smaller is required by the MRF2D code to reach the same precision on criticality eigenvalue. (Author) [pt
International Nuclear Information System (INIS)
Craps, Ben; Evnin, Oleg; Nguyen, Kévin
2017-01-01
Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.
Craps, Ben; Evnin, Oleg; Nguyen, Kévin
2017-02-01
Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.
Energy Technology Data Exchange (ETDEWEB)
Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Evnin, Oleg [Department of Physics, Faculty of Science, Chulalongkorn University, Thanon Phayathai, Pathumwan, Bangkok 10330 (Thailand); Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Nguyen, Kévin [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB), and International Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium)
2017-02-08
Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.
Lee, Yujung; Kwon, Jeongil; Khang, Gilson; Lee, Dongwon
2012-10-01
Vanillin is one of the major components of vanilla, a commonly used flavoring agent and preservative and is known to exert potent antioxidant and anti-inflammatory activities. In this work, vanillin-incorporated poly(lactic-co-glycolic acid) (PLGA) films and scaffolds were fabricated to evaluate the effects of vanillin on the inflammatory responses and extracellular matrix (ECM) formation in vitro and in vivo. The incorporation of vanillin to PLGA films induced hydrophilic nature, resulting in the higher cell attachment and proliferation than the pure PLGA film. Vanillin also reduced the generation of reactive oxygen species (ROS) in cells cultured on the pure PLGA film and significantly inhibited the PLGA-induced inflammatory responses in vivo, evidenced by the reduced accumulation of inflammatory cells and thinner fibrous capsules. The effects of vanillin on the ECM formation were evaluated using annulus fibrous (AF) cell-seeded porous PLGA/vanillin scaffolds. PLGA/vanillin scaffolds elicited the more production of glycosaminoglycan and collagen than the pure PLGA scaffold, in a concentration-dependent manner. Based on the low level of inflammatory responses and enhanced ECM formation, vanillin-incorporated PLGA constructs make them promising candidates in the future biomedical applications.
Lee, Yujung; Kwon, Jeongil; Khang, Gilson
2012-01-01
Vanillin is one of the major components of vanilla, a commonly used flavoring agent and preservative and is known to exert potent antioxidant and anti-inflammatory activities. In this work, vanillin-incorporated poly(lactic-co-glycolic acid) (PLGA) films and scaffolds were fabricated to evaluate the effects of vanillin on the inflammatory responses and extracellular matrix (ECM) formation in vitro and in vivo. The incorporation of vanillin to PLGA films induced hydrophilic nature, resulting in the higher cell attachment and proliferation than the pure PLGA film. Vanillin also reduced the generation of reactive oxygen species (ROS) in cells cultured on the pure PLGA film and significantly inhibited the PLGA-induced inflammatory responses in vivo, evidenced by the reduced accumulation of inflammatory cells and thinner fibrous capsules. The effects of vanillin on the ECM formation were evaluated using annulus fibrous (AF) cell-seeded porous PLGA/vanillin scaffolds. PLGA/vanillin scaffolds elicited the more production of glycosaminoglycan and collagen than the pure PLGA scaffold, in a concentration-dependent manner. Based on the low level of inflammatory responses and enhanced ECM formation, vanillin-incorporated PLGA constructs make them promising candidates in the future biomedical applications. PMID:22551555
International Nuclear Information System (INIS)
Owens, D.H.
1972-06-01
The KDF9/EGDON programme FADDEEV has been written to investigate a technique for the calculation of the matrix of frequency responses G(jw) describing the response of the output vector y from the multivariable differential/algebraic system S to the drive of the system input vector u. S: Ex = Ax + Bu, y = Cx, G(jw) = C(jw E - A ) -1 B. The programme uses an algorithm due to Faddeev and has been written with emphasis upon: (a) simplicity of programme structure and computational technique which should enable a user to find his way through the programme fairly easily, and hence facilitate its manipulation as a subroutine in a larger code; (b) rapid computational ability, particularly in systems with fairly large number of inputs and outputs and requiring the evaluation of the frequency responses at a large number of frequencies. Transport or time delays must be converted by the user to Pade or Bode approximations prior to input. Conditions under which the algorithm fails to give accurate results are identified, and methods for increasing the accuracy of the calculations are discussed. The conditions for accurate results using FADDEEV indicate that its application is specialized. (author)
Damanik, Febriyani F R; Rothuizen, Tonia C; van Blitterswijk, Clemens; Rotmans, Joris I; Moroni, Lorenzo
2014-09-19
Despite various studies to minimize host reaction following a biomaterial implantation, an appealing strategy in regenerative medicine is to actively use such an immune response to trigger and control tissue regeneration. We have developed an in vitro model to modulate the host response by tuning biomaterials' surface properties through surface modifications techniques as a new strategy for tissue regeneration applications. Results showed tunable surface topography, roughness, wettability, and chemistry by varying treatment type and exposure, allowing for the first time to correlate the effect of these surface properties on cell attachment, morphology, strength and proliferation, as well as proinflammatory (IL-1β, IL-6) and antiinflammatory cytokines (TGF-β1, IL-10) secreted in medium, and protein expression of collagen and elastin. Surface microstructuring, derived from chloroform partial etching, increased surface roughness and oxygen content. This resulted in enhanced cell adhesion, strength and proliferation as well as a balance of soluble factors for optimum collagen and elastin synthesis for tissue regeneration. By linking surface parameters to cell activity, we could determine the fate of the regenerated tissue to create successful soft tissue-engineered replacement.
Linear Magnetoelectric Effect by Orbital Magnetism
Scaramucci, A.; Bousquet, E.; Fechner, M.; Mostovoy, M.; Spaldin, N. A.
2012-01-01
We use symmetry analysis and first-principles calculations to show that the linear magnetoelectric effect can originate from the response of orbital magnetic moments to the polar distortions induced by an applied electric field. Using LiFePO4 as a model compound we show that spin-orbit coupling
Asteroid orbital error analysis: Theory and application
Muinonen, K.; Bowell, Edward
1992-01-01
We present a rigorous Bayesian theory for asteroid orbital error estimation in which the probability density of the orbital elements is derived from the noise statistics of the observations. For Gaussian noise in a linearized approximation the probability density is also Gaussian, and the errors of the orbital elements at a given epoch are fully described by the covariance matrix. The law of error propagation can then be applied to calculate past and future positional uncertainty ellipsoids (Cappellari et al. 1976, Yeomans et al. 1987, Whipple et al. 1991). To our knowledge, this is the first time a Bayesian approach has been formulated for orbital element estimation. In contrast to the classical Fisherian school of statistics, the Bayesian school allows a priori information to be formally present in the final estimation. However, Bayesian estimation does give the same results as Fisherian estimation when no priori information is assumed (Lehtinen 1988, and reference therein).
International Nuclear Information System (INIS)
Lougovski, Alexandr; Hofheinz, Frank; Maus, Jens; Schramm, Georg; Van den Hoff, Jörg
2015-01-01
We investigate the question of how the blob approach is related to tube of response based modelling of the system matrix. In our model, the tube of response (TOR) is approximated as a cylinder with constant density (TOR-CD) and the cubic voxels are replaced by spheres. Here we investigate a modification of the TOR model that makes it effectively equivalent to the blob model, which models the intersection of lines of response (LORs) with radially variant basis functions (‘blobs’) replacing the cubic voxels. Implications of the achieved equivalence regarding the necessity of final resampling in blob-based reconstructions are considered. We extended TOR-CD to a variable density tube model (TOR-VD) that yields a weighting function (defining all system matrix elements) which is essentially identical to that of the blob model. The variable density of TOR-VD was modelled by a Gaussian and a Kaiser–Bessel function, respectively. The free parameters of both model functions were determined by fitting the corresponding weighting function to the weighting function of the blob model. TOR-CD and the best-fitting TOR-VD were compared to the blob model with a final resampling step (BLOB-RS) and without resampling (BLOB-NRS) in phantom studies. For three different contrast ratios and two different voxel sizes, resolution noise curves were generated. TOR-VD and BLOB-NRS lead to nearly identical images for all investigated contrast ratios and voxel sizes. Both models showed strong Gibbs artefacts at 4 mm voxel size, while at 2 mm voxel size there were no Gibbs artefacts visible. The spatial resolution was similar to the resolution with TOR-CD in all cases. The resampling step removed most of the Gibbs artefacts and reduced the noise level but also degraded the spatial resolution substantially. We conclude that the blob model can be considered just as a special case of a TOR-based reconstruction. The latter approach provides a more natural description of the detection process
Morgan-Fisher, Marie; Wait, Robin; Couchman, John R.; Wewer, Ulla M.
2012-01-01
Collapsin response mediator protein 2 (CRMP-2) is known as a regulator of neuronal polarity and differentiation through microtubule assembly and trafficking. Here, we show that CRMP-2 is ubiquitously expressed and a splice variant (CRMP-2L), which is expressed mainly in epithelial cells among nonneuronal cells, regulates myosin II-mediated cellular functions, including cell migration. While the CRMP-2 short form (CRMP-2S) is recognized as a substrate of the Rho-GTP downstream kinase ROCK in neuronal cells, a CRMP-2 complex containing 2L not only bound the catalytic domain of ROCK II through two binding domains but also trapped and inhibited the kinase. CRMP-2L protein levels profoundly affected haptotactic migration and the actin-myosin cytoskeleton of carcinoma cells as well as nontransformed epithelial cell migration in a ROCK activity-dependent manner. Moreover, the ectopic expression of CRMP-2L but not -2S inhibited fibronectin matrix assembly in fibroblasts. Underlying these responses, CRMP-2L regulated the kinase activity of ROCK II but not ROCK I, independent of GTP-RhoA levels. This study provides a new insight into CRMP-2 as a controller of myosin II-mediated cellular functions through the inhibition of ROCK II in nonneuronal cells. PMID:22431514
Borumandi, Farzad
2013-01-01
Compared to the cerebrospinalfluid (CSF) leak through the nose and ear, the orbital CSF leak is a rare and underreported condition following head trauma. We present the case of a 49-year-old woman with oedematous eyelid swelling and ecchymosis after a seemingly trivial fall onto the right orbit. Apart from the above, she was clinically unremarkable. The CT scan revealed a minimally displaced fracture of the orbital roof with no emphysema or intracranial bleeding. The fractured orbital roof in combination with the oedematous eyelid swelling raised the suspicion for orbital CSF leak. The MRI of the neurocranium demonstrated a small-sized CSF fistula extending from the anterior cranial fossa to the right orbit. The patient was treated conservatively and the lid swelling resolved completely after 5 days. Although rare, orbital CSF leak needs to be included in the differential diagnosis of periorbital swelling following orbital trauma. PMID:24323381
Zhan, Xingzhi
2002-01-01
The main purpose of this monograph is to report on recent developments in the field of matrix inequalities, with emphasis on useful techniques and ingenious ideas. Among other results this book contains the affirmative solutions of eight conjectures. Many theorems unify or sharpen previous inequalities. The author's aim is to streamline the ideas in the literature. The book can be read by research workers, graduate students and advanced undergraduates.
International Nuclear Information System (INIS)
Panfilova, G.V.; Koval', G.Yu.
1984-01-01
Radioanatomy of eyes and orbit is described. Diseases of the orbit (developmental anomalies, inflammatory diseases, lacrimal apparatus deseases, toxoplasmosis, tumors and cysts et al.), methods of foreign body localization in the eye are considered. Roentgenograms of the orbit and calculation table for foreign body localization in spherical eyes of dissimilar diameter are presented
National Research Council Canada - National Science Library
Woodward, Terry
1997-01-01
Specific extracellular matrix (ECM) proteins and their cellular receptors (integrins) are required for normal mammary gland morphogenesis and differentiation, while their expression is dramatically altered during tumorigenesis...
Space station orbit maintenance
Kaplan, D. I.; Jones, R. M.
1983-01-01
The orbit maintenance problem is examined for two low-earth-orbiting space station concepts - the large, manned Space Operations Center (SOC) and the smaller, unmanned Science and Applications Space Platform (SASP). Atmospheric drag forces are calculated, and circular orbit altitudes are selected to assure a 90 day decay period in the event of catastrophic propulsion system failure. Several thrusting strategies for orbit maintenance are discussed. Various chemical and electric propulsion systems for orbit maintenance are compared on the basis of propellant resupply requirements, power requirements, Shuttle launch costs, and technology readiness.
Nontraumatic orbital roof encephalocele.
Hoang, Amber; Maugans, Todd; Ngo, Thang; Ikeda, Jamie
2017-02-01
Intraorbital meningoencephaloceles occur most commonly as a complication of traumatic orbital roof fractures. Nontraumatic congenital orbital meningoncephaloceles are very rare, with most secondary to destructive processes affecting the orbit and primary skull defects. Treatment for intraorbital meningoencephaloceles is surgical repair, involving the excision of herniated brain parenchyma and meninges and reconstruction of the osseous defect. Most congenital lesions present in infancy with obvious globe and orbital deformities; we report an orbital meningoencephalocele in a 3-year-old girl who presented with ptosis. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.
Schmidt-Kalman Filter with Polynomial Chaos Expansion for Orbit Determination of Space Objects
Yang, Y.; Cai, H.; Zhang, K.
2016-09-01
Parameter errors in orbital models can result in poor orbit determination (OD) using a traditional Kalman filter. One approach to account for these errors is to consider them in the so-called Schmidt-Kalman filter (SKF), by augmenting the state covariance matrix (CM) with additional parameter covariance rather than additively estimating these so-called "consider" parameters. This paper introduces a new SKF algorithm with polynomial chaos expansion (PCE-SKF). The PCE approach has been proved to be more efficient than Monte Carlo method for propagating the input uncertainties onto the system response without experiencing any constraints of linear dynamics, or Gaussian distributions of the uncertainty sources. The state and covariance needed in the orbit prediction step are propagated using PCE. An inclined geosynchronous orbit scenario is set up to test the proposed PCE-SKF based OD algorithm. The satellite orbit is propagated based on numerical integration, with the uncertain coefficient of solar radiation pressure considered. The PCE-SKF solutions are compared with extended Kalman filter (EKF), SKF and PCE-EKF (EKF with PCE) solutions. It is implied that the covariance propagation using PCE leads to more precise OD solutions in comparison with those based on linear propagation of covariance.
Periodic orbits around areostationary points in the Martian gravity field
International Nuclear Information System (INIS)
Liu Xiaodong; Baoyin Hexi; Ma Xingrui
2012-01-01
This study investigates the problem of areostationary orbits around Mars in three-dimensional space. Areostationary orbits are expected to be used to establish a future telecommunication network for the exploration of Mars. However, no artificial satellites have been placed in these orbits thus far. The characteristics of the Martian gravity field are presented, and areostationary points and their linear stability are calculated. By taking linearized solutions in the planar case as the initial guesses and utilizing the Levenberg-Marquardt method, families of periodic orbits around areostationary points are shown to exist. Short-period orbits and long-period orbits are found around linearly stable areostationary points, but only short-period orbits are found around unstable areostationary points. Vertical periodic orbits around both linearly stable and unstable areostationary points are also examined. Satellites in these periodic orbits could depart from areostationary points by a few degrees in longitude, which would facilitate observation of the Martian topography. Based on the eigenvalues of the monodromy matrix, the evolution of the stability index of periodic orbits is determined. Finally, heteroclinic orbits connecting the two unstable areostationary points are found, providing the possibility for orbital transfer with minimal energy consumption.
Hamilton, Douglas P.
2018-04-01
Solar radiation pressure is usually very effective at removing hazardous millimeter-sized debris from distant orbits around asteroidsand other small solar system bodies (Hamilton and Burns 1992). Theprimary loss mechanism, driven by the azimuthal component of radiationpressure, is eccentricity growth followed by a forced collision withthe central body. One large class of orbits, however, neatly sidestepsthis fate. Orbits oriented nearly perpendicular to the solar directioncan maintain their face-on geometry, oscillating slowly around a stableequilibrium orbit. These orbits, designated sunflower orbits, arerelated to terminator orbits studied by spacecraft mission designers(Broschart etal. 2014).Destabilization of sunflower orbits occurs only for particles smallenough that radiation pressure is some tens of percent the strength ofthe central body's direct gravity. This greatly enhanced stability,which follows from the inability of radiation incident normal to theorbit to efficiently drive eccentricities, presents a threat tospacecraft missions, as numerous dangerous projectiles are potentiallyretained in orbit. We have investigated sunflower orbits insupport of the New Horizons, Aida, and Lucy missions and find thatthese orbits are stable for hazardous particle sizes at asteroids,comets, and Kuiper belt objects of differing dimensions. Weinvestigate the sources and sinks for debris that might populate suchorbits, estimate timescales and equilibrium populations, and willreport on our findings.
Directory of Open Access Journals (Sweden)
Jeffrey M Joseph
2011-01-01
Full Text Available Jeffrey M Joseph, Ioannis P GlavasDivision of Ophthalmic Plastic and Reconstructive Surgery, Department of Ophthalmology, School of Medicine, New York University, New York, NY, USA; Manhattan Eye, Ear, and Throat Hospital, New York, NY, USAAbstract: This review of orbital fractures has three goals: 1 to understand the clinically relevant orbital anatomy with regard to periorbital trauma and orbital fractures, 2 to explain how to assess and examine a patient after periorbital trauma, and 3 to understand the medical and surgical management of orbital fractures. The article aims to summarize the evaluation and management of commonly encountered orbital fractures from the ophthalmologic perspective and to provide an overview for all practicing ophthalmologists and ophthalmologists in training.Keywords: orbit, trauma, fracture, orbital floor, medial wall, zygomatic, zygomatic complex, zmc fracture, zygomaticomaxillary complex fractures
Directory of Open Access Journals (Sweden)
Stephanie Christau
2014-06-01
Full Text Available The effect of brush thickness on the loading of gold nanoparticles (AuNPs within stimuli-responsive poly-(N,N-(dimethylamino ethyl methacrylate (PDMAEMA polyelectrolyte brushes is reported. Atom transfer radical polymerization (ATRP was used to grow polymer brushes via a “grafting from” approach. The brush thickness was tuned by varying the polymerization time. Using a new type of sealed reactor, thick brushes were synthesized. A systematic study was performed by varying a single parameter (brush thickness, while keeping all other parameters constant. AuNPs of 13 nm in diameter were attached by incubation. X-ray reflectivity, electron scanning microscopy and ellipsometry were used to study the particle loading, particle distribution and interpenetration of the particles within the brush matrix. A model for the structure of the brush/particle hybrids was derived. The particle number densities of attached AuNPs depend on the brush thickness, as do the optical properties of the hybrids. An increasing particle number density was found for increasing brush thickness, due to an increased surface roughness.
International Nuclear Information System (INIS)
Saddi, M.B.; Singh, Bhajan; Sandhu, B.S.
2008-01-01
The collision integral cross-sections of double-photon Compton process are measured experimentally for 662 keV incident gamma photons. The measurements are successfully carried out using a single gamma ray detector, and do not require the complicated slow-fast coincidence technique used till now for observing this higher order quantum electrodynamics (QED) process. The energy spectra of one of the two final photons, originating in this process, in direction of the gamma ray detector are observed as a long tail to the single-photon Compton line on lower side of the full energy peak in the observed spectra. An inverse response matrix converts the observed pulse-height distribution of a NaI(Tl) scintillation detector to a true photon spectrum. This also results in extraction of events originating from double-photon Compton interactions. The present measured values of collision integral cross-section, although of same magnitude, deviate from the corresponding values obtained from the theory. In view of the magnitude of deviations, in addition to small value of probability of occurrence of this process, the agreement of measured values with theory is reasonably acceptable
Bhatia, Rajendra
1997-01-01
A good part of matrix theory is functional analytic in spirit. This statement can be turned around. There are many problems in operator theory, where most of the complexities and subtleties are present in the finite-dimensional case. My purpose in writing this book is to present a systematic treatment of methods that are useful in the study of such problems. This book is intended for use as a text for upper division and gradu ate courses. Courses based on parts of the material have been given by me at the Indian Statistical Institute and at the University of Toronto (in collaboration with Chandler Davis). The book should also be useful as a reference for research workers in linear algebra, operator theory, mathe matical physics and numerical analysis. A possible subtitle of this book could be Matrix Inequalities. A reader who works through the book should expect to become proficient in the art of deriving such inequalities. Other authors have compared this art to that of cutting diamonds. One first has to...
Bolbrinker, J; Markovic, S; Wehland, M; Melenhorst, WBWH; van Goor, H; Kreutz, R
Extracellular matrix expansion in the glomerular mesangium contributes to the development of glomerulosclerosis and chronic renal disease in arterial hypertension. Transforming growth factor-beta 1 (TGF-beta 1), matrix metalloproteinases (MMPs), and tissue inhibitors of MMPs (TIMPs) are involved in
Brenner, Barbara; Schlegelmilch, Bodo B.; Ambos, Björn
2013-01-01
This case describes how Nike, a consumer goods company with an ever expanding portfolio and a tremendous brand value, manages the tradeoff between local responsiveness and global integration. In particular, the case highlights Nike's organizational structure that consists of a global matrix organization that is replicated at a regional level for the European market. While this organizational structure allows Nike to respond to local consumer tastes it also ensures that the company benefits f...
Belitsky, A. V.
2017-10-01
The Operator Product Expansion for null polygonal Wilson loop in planar maximally supersymmetric Yang-Mills theory runs systematically in terms of multi-particle pentagon transitions which encode the physics of excitations propagating on the color flux tube ending on the sides of the four-dimensional contour. Their dynamics was unraveled in the past several years and culminated in a complete description of pentagons as an exact function of the 't Hooft coupling. In this paper we provide a solution for the last building block in this program, the SU(4) matrix structure arising from internal symmetry indices of scalars and fermions. This is achieved by a recursive solution of the Mirror and Watson equations obeyed by the so-called singlet pentagons and fixing the form of the twisted component in their tensor decomposition. The non-singlet, or charged, pentagons are deduced from these by a limiting procedure.
Directory of Open Access Journals (Sweden)
A.V. Belitsky
2017-10-01
Full Text Available The Operator Product Expansion for null polygonal Wilson loop in planar maximally supersymmetric Yang–Mills theory runs systematically in terms of multi-particle pentagon transitions which encode the physics of excitations propagating on the color flux tube ending on the sides of the four-dimensional contour. Their dynamics was unraveled in the past several years and culminated in a complete description of pentagons as an exact function of the 't Hooft coupling. In this paper we provide a solution for the last building block in this program, the SU(4 matrix structure arising from internal symmetry indices of scalars and fermions. This is achieved by a recursive solution of the Mirror and Watson equations obeyed by the so-called singlet pentagons and fixing the form of the twisted component in their tensor decomposition. The non-singlet, or charged, pentagons are deduced from these by a limiting procedure.
Effects and Correction of Closed Orbit Magnet Errors in the SNS Ring
Energy Technology Data Exchange (ETDEWEB)
Bunch, S.C.; Holmes, J.
2004-01-01
We consider the effect and correction of three types of orbit errors in SNS: quadrupole displacement errors, dipole displacement errors, and dipole field errors. Using the ORBIT beam dynamics code, we focus on orbit deflection of a standard pencil beam and on beam losses in a high intensity injection simulation. We study the correction of these orbit errors using the proposed system of 88 (44 horizontal and 44 vertical) ring beam position monitors (BPMs) and 52 (24 horizontal and 28 vertical) dipole corrector magnets. Correction is carried out numerically by adjusting the kick strengths of the dipole corrector magnets to minimize the sum of the squares of the BPM signals for the pencil beam. In addition to using the exact BPM signals as input to the correction algorithm, we also consider the effect of random BPM signal errors. For all three types of error and for perturbations of individual magnets, the correction algorithm always chooses the three-bump method to localize the orbit displacement to the region between the magnet and its adjacent correctors. The values of the BPM signals resulting from specified settings of the dipole corrector kick strengths can be used to set up the orbit response matrix, which can then be applied to the correction in the limit that the signals from the separate errors add linearly. When high intensity calculations are carried out to study beam losses, it is seen that the SNS orbit correction system, even with BPM uncertainties, is sufficient to correct losses to less than 10-4 in nearly all cases, even those for which uncorrected losses constitute a large portion of the beam.
Kondyurin, Alexey; Kondyurina, Irina; Bilek, Marcela; de Groh, Kim K.
2013-01-01
A cassette of uncured composite materials with epoxy resin matrixes was exposed in the stratosphere (40 km altitude) over three days. Temperature variations of -76 to 32.5C and pressure up to 2.1 torr were recorded during flight. An analysis of the chemical structure of the composites showed, that the polymer matrix exposed in the stratosphere becomes crosslinked, while the ground control materials react by way of polymerization reaction of epoxy groups. The space irradiations are considered to be responsible for crosslinking of the uncured polymers exposed in the stratosphere. The composites were cured on Earth after landing. Analysis of the cured composites showed that the polymer matrix remains active under stratospheric conditions. The results can be used for predicting curing processes of polymer composites in a free space environment during an orbital space flight.
Aiyub, Shereen; Chan, Weng Onn; Szetu, John; Sullivan, Laurence J; Pater, John; Cooper, Peter; Selva, Dinesh
2013-01-01
We present a case of mature congenital orbital teratoma managed with lid-sparing exenteration and dermis fat graft. This is a case report on the management of congenital orbital teratoma. A full-term baby was born in Fiji with prolapsed right globe which was surrounded by a nonpulsatile, cystic mass. Clinical and imaging features were consistent with congenital orbital teratoma. Due to limited surgical expertise, the patient was transferred to Adelaide, Australia for further management. The p...
Pictorial essay: Orbital tuberculosis
International Nuclear Information System (INIS)
Narula, Mahender K; Chaudhary, Vikas; Baruah, Dhiraj; Kathuria, Manoj; Anand, Rama
2010-01-01
Tuberculosis of the orbit is rare, even in places where tuberculosis is endemic. The disease may involve soft tissue, the lacrimal gland, or the periosteum or bones of the orbital wall. Intracranial extension, in the form of extradural abscess, and infratemporal fossa extension has been described. This pictorial essay illustrates the imaging findings of nine histopathologically confirmed cases of orbital tuberculosis. All these patients responded to antituberculous treatment
International Nuclear Information System (INIS)
Kelly, J.K.; Lazo, A.; Metes, J.J.
1988-01-01
Computed tomography has become the gold standard against which to measure orbital imaging modalities. The simultaneous display of bone, soft tissues, paranasal sinuses, and intracranial structures is a unique advantage. Radiation dose and cost have been cited as disadvantages. These would suggest that CT be reserved for the patient with significant orbital injury or difficult diagnostic problems. Magnetic resonance is limited in the investigation of orbital trauma
Directory of Open Access Journals (Sweden)
Khalil M Al-Salem
2014-01-01
Full Text Available Orbital complications due to ethmoiditis are rare in neonates. A case of orbital abscess due to acute ethmoiditis in a 28-day-old girl is presented. A Successful outcome was achieved following antimicrobial therapy alone; spontaneous drainage of the abscess occurred from the lower lid without the need for surgery. From this case report, we intend to emphasize on eyelid retraction as a sign of neonatal orbital abscess, and to review all the available literature of similar cases.
Radial Matrix Elements of Hydrogen Atom and the Correspondence ...
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
Hydrogen excited states—radial matrix element—corres- ... atoms, its availability, production, its spectras, and importance in astrophysics (Dupree ... far away revolving lazily around in a slow orbit like a distant planet in the solar system. As the electron orbit diameter grows rapidly, its energy also decreases rapidly. Currently ...
International Nuclear Information System (INIS)
Kusmartsev, F.V.
1992-10-01
The physical reasons why the orbital glass may exist in granular high-temperature superconductors and the existing experimental data appeared recently are discussed. The orbital glass is characterized by the coexistence of the orbital paramagnetic state with the superconducting state and occurs at small magnetic fields H c0 c1 . The transition in orbital glass arises at the critical field H c0 which is inversely proportional to the surface cross-area S of an average grain. In connection with theoretical predictions the possible experiments are proposed. (author). 10 refs
Use of regularization method in the determination of ring parameters and orbit correction
International Nuclear Information System (INIS)
Tang, Y.N.; Krinsky, S.
1993-01-01
We discuss applying the regularization method of Tikhonov to the solution of inverse problems arising in accelerator operations. This approach has been successfully used for orbit correction on the NSLS storage rings, and is presently being applied to the determination of betatron functions and phases from the measured response matrix. The inverse problem of differential equation often leads to a set of integral equations of the first kind which are ill-conditioned. The regularization method is used to combat the ill-posedness
Zhang, Yunlin; Liu, Xiaohan; Osburn, Christopher L; Wang, Mingzhu; Qin, Boqiang; Zhou, Yongqiang
2013-01-01
CDOM biogeochemical cycle is driven by several physical and biological processes such as river input, biogeneration and photobleaching that act as primary sinks and sources of CDOM. Watershed-derived allochthonous (WDA) and phytoplankton-derived autochthonous (PDA) CDOM were exposed to 9 days of natural solar radiation to assess the photobleaching response of different CDOM sources, using absorption and fluorescence (excitation-emission matrix) spectroscopy. Our results showed a marked decrease in total dissolved nitrogen (TDN) concentration under natural sunlight exposure for both WDA and PDA CDOM, indicating photoproduction of ammonium from TDN. In contrast, photobleaching caused a marked increase in total dissolved phosphorus (TDP) concentration for both WDA and PDA CDOM. Thus TDN:TDP ratios decreased significantly both for WDA and PDA CDOM, which partially explained the seasonal dynamic of TDN:TDP ratio in Lake Taihu. Photobleaching rate of CDOM absorption a(254), was 0.032 m/MJ for WDA CDOM and 0.051 m/MJ for PDA CDOM from days 0-9, indicating that phototransformations were initially more rapid for the newly produced CDOM from phytoplankton than for the river CDOM. Extrapolation of these values to the field indicated that 3.9%-5.1% CDOM at the water surface was photobleached and mineralized every day in summer in Lake Taihu. Photobleaching caused the increase of spectral slope, spectral slope ratio and molecular size, indicating the CDOM mean molecular weight decrease which was favorable to further microbial degradation of mineralization. Three fluorescent components were validated in parallel factor analysis models calculated separately for WDA and PDA CDOM. Our study suggests that the humic-like fluorescence materials could be rapidly and easily photobleached for WDA and PDA CDOM, but the protein-like fluorescence materials was not photobleached and even increased from the transformation of the humic-like fluorescence substance to the protein
Frozen orbit realization using LQR analogy
Nagarajan, N.; Rayan, H. Reno
In the case of remote sensing orbits, the Frozen Orbit concept minimizes altitude variations over a given region using passive means. This is achieved by establishing the mean eccentricity vector at the orbital poles i.e., by fixing the mean argument of perigee at 90 deg with an appropriate eccentricity to balance the perturbations due to zonal harmonics J2 and J3 of the Earth's potential. Eccentricity vector is a vector whose magnitude is the eccentricity and direction is the argument of perigee. The launcher dispersions result in an eccentricity vector which is away from the frozen orbit values. The objective is then to formulate an orbit maneuver strategy to optimize the fuel required to achieve the frozen orbit in the presence of visibility and impulse constraints. It is shown that the motion of the eccentricity vector around the frozen perigee can be approximated as a circle. Combining the circular motion of the eccentricity vector around the frozen point and the maneuver equation, the following discrete equation is obtained. X(k+1) = AX(k) + Bu(k), where X is the state (i.e. eccentricity vector components), A the state transition matrix, u the scalar control force (i.e. dV in this case) and B the control matrix which transforms dV into eccentricity vector change. Based on this, it is shown that the problem of optimizing the fuel can be treated as a Linear Quadratic Regulator (LQR) problem in which the maneuver can be solved by using control system design tools like MATLAB by deriving an analogy LQR design.
Ghost Imaging Using Orbital Angular Momentum
Institute of Scientific and Technical Information of China (English)
赵生妹; 丁建; 董小亮; 郑宝玉
2011-01-01
We present a novel encoding scheme in a ghost-imaging system using orbital angular momentum. In the signal arm, object spatial information is encoded as a phase matrix. For an N-grey-scale object, different phase matrices, varying from 0 to K with increment n/N, are used for different greyscales, and then they are modulated to a signal beam by a spatial light modulator. According to the conservation of the orbital angular momentum in the ghost imaging system, these changes will give different coincidence rates in measurement, and hence the object information can be extracted in the idler arm. By simulations and experiments, the results show that our scheme can improve the resolution of the image effectively. Compared with another encoding method using orbital angular momentum, our scheme has a better performance for both characters and the image object.%We present a novel encoding scheme in a ghost-imaging system using orbital angular momentum.In the signal arm,object spatial information is encoded as a phase matrix.For an N-grey-scale object,different phase matrices,varying from 0 to π with increment π/N,are used for different greyscales,and then they are modulated to a signal beam by a spatial light modulator.According to the conservation of the orbital angular momentum in the ghost imaging system,these changes will give different coincidence rates in measurement,and hence the object information can be extracted in the idler arm.By simulations and experiments,the results show that our scheme can improve the resolution of the image effectively.Compared with another encoding method using orbital angular momentum,our scheme has a better performance for both characters and the image object.
Congenital orbital encephalocele, orbital dystopia, and exophthalmos.
Hwang, Kun; Kim, Han Joon
2012-07-01
We present here an exceedingly rare variant of a nonmidline basal encephalocele of the spheno-orbital type, and this was accompanied with orbital dystopia in a 56-year-old man. On examination, his left eye was located more inferolaterally than his right eye, and the patient said this had been this way since his birth. The protrusion of his left eye was aggravated when he is tired. His naked visual acuity was 0.7/0.3, and the ocular pressure was 14/12 mm Hg. The exophthalmometry was 10/14 to 16 mm. His eyeball motion was not restricted, yet diplopia was present in all directions. The distance from the midline to the medial canthus was 20/15 mm. The distance from the midline to the midpupillary line was 35/22 mm. The vertical dimension of the palpebral fissure was 12/9 mm. The height difference of the upper eyelid margin was 11 mm, and the height difference of the lower eyelid margin was 8 mm. Facial computed tomography and magnetic resonance imaging showed left sphenoid wing hypoplasia and herniation of the left anterior temporal pole and dura mater into the orbit, and this resulted into left exophthalmos and encephalomalacia in the left anterior temporal pole. To the best of our knowledge, our case is the second case of basal encephalocele and orbital dystopia.
Charge-spin-orbital dynamics of one-dimensional two-orbital Hubbard model
Energy Technology Data Exchange (ETDEWEB)
Onishi, Hiroaki [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)
2010-01-15
We study the real-time evolution of a charge-excited state in a one-dimensional e{sub g}-orbital degenerate Hubbard model, by a time-dependent density-matrix renormalization group method. Considering a chain along the z direction, electrons hop between adjacent 3z{sup 2}-r{sup 2} orbitals, while x{sup 2}-y{sup 2} orbitals are localized. For the charge-excited state, a holon-doublon pair is introduced into the ground state at quarter filling. At initial time, there is no electron in a holon site, while a pair of electrons occupies 3z{sup 2}-r{sup 2} orbital in a doublon site. As the time evolves, the holon motion is governed by the nearest-neighbor hopping, but the electron pair can transfer between 3z{sup 2}-r{sup 2} orbital and x{sup 2}-y{sup 2} orbital through the pair hopping in addition to the nearest-neighbor hopping. Thus holon and doublon propagate at different speed due to the pair hopping that is characteristic of multi-orbital systems.
Titan Orbiter Aerorover Mission
Sittler Jr., E. C.; Acuna, M.; Burchell, M. J.; Coates, A.; Farrell, W.; Flasar, M.; Goldstein, B. E.; Gorevan, S.; Hartle, R. E.; Johnson, W. T. K.
2001-01-01
We propose a combined Titan orbiter and Titan Aerorover mission with an emphasis on both in situ and remote sensing measurements of Titan's surface, atmosphere, ionosphere, and magnetospheric interaction. The biological aspect of the Titan environment will be emphasized by the mission (i.e., search for organic materials which may include simple organics to 'amono' analogues of amino acids and possibly more complex, lightening detection and infrared, ultraviolet, and charged particle interactions with Titan's surface and atmosphere). An international mission is assumed to control costs. NASA will provide the orbiter, launch vehicle, DSN coverage and operations, while international partners will provide the Aerorover and up to 30% of the cost for the scientific instruments through collaborative efforts. To further reduce costs we propose a single PI for orbiter science instruments and a single PI for Aerorover science instruments. This approach will provide single command/data and power interface between spacecraft and orbiter instruments that will have redundant central DPU and power converter for their instruments. A similar approach could be used for the Aerorover. The mission profile will be constructed to minimize conflicts between Aerorover science, orbiter radar science, orbiter radio science, orbiter imaging science, and orbiter fields and particles (FP) science. Additional information is contained in the original extended abstract.
Orbital and adnexal sarcoidosis
Prabhakaran, Venkatesh C.; Saeed, Perooz; Esmaeli, Bita; Sullivan, Timothy J.; Mcnab, Alan; Davis, Garry; Valenzuela, Alejandra; Leibovitch, Igal; Kesler, Anat; Sivak-Callcott, Jennifer; Hoyama, Erika; Selva, Dinesh
2007-01-01
To present the clinical features and management in a series of patients with orbital and adnexal sarcoidosis. This multicenter retrospective study included patients with biopsy-proven noncaseating granuloma involving the orbit or adnexa and evidence of systemic sarcoidosis. Clinical records were
Update on orbital reconstruction.
Chen, Chien-Tzung; Chen, Yu-Ray
2010-08-01
Orbital trauma is common and frequently complicated by ocular injuries. The recent literature on orbital fracture is analyzed with emphasis on epidemiological data assessment, surgical timing, method of approach and reconstruction materials. Computed tomographic (CT) scan has become a routine evaluation tool for orbital trauma, and mobile CT can be applied intraoperatively if necessary. Concomitant serious ocular injury should be carefully evaluated preoperatively. Patients presenting with nonresolving oculocardiac reflex, 'white-eyed' blowout fracture, or diplopia with a positive forced duction test and CT evidence of orbital tissue entrapment require early surgical repair. Otherwise, enophthalmos can be corrected by late surgery with a similar outcome to early surgery. The use of an endoscope-assisted approach for orbital reconstruction continues to grow, offering an alternative method. Advances in alloplastic materials have improved surgical outcome and shortened operating time. In this review of modern orbital reconstruction, several controversial issues such as surgical indication, surgical timing, method of approach and choice of reconstruction material are discussed. Preoperative fine-cut CT image and thorough ophthalmologic examination are key elements to determine surgical indications. The choice of surgical approach and reconstruction materials much depends on the surgeon's experience and the reconstruction area. Prefabricated alloplastic implants together with image software and stereolithographic models are significant advances that help to more accurately reconstruct the traumatized orbit. The recent evolution of orbit reconstruction improves functional and aesthetic results and minimizes surgical complications.
International Nuclear Information System (INIS)
Iinuma, Toshitaka; Ishio, Ken-ichirou; Yoshinami, Hiroyoshi; Kuriyama, Jun-ichi; Hirota, Yoshiharu.
1993-01-01
A total of 59 cases of mild facial fractures (simple orbital wall fractures, 34 cases, other facial fractures, 25 cases) with the clinical suspects of orbital wall fractures were evaluated both by conventional views (Waters' and Caldwell views) and coronal CT scans. Conventional views were obtained, as an average, after 4 days and CT after 7 days of injuries. Both the medial wall and the floor were evaluated at two sites, i.e., anterior and posterior. The ethmoid-maxillary plate was also included in the study. The degree of fractures was classified as, no fractures, fractures of discontinuity, dislocation and fragmentation. The coronal CT images in bone window condition was used as reference and the findings were compared between conventional views and CT. The correct diagnosis was obtained as follows: orbital floor (anterior, 78%, posterior, 73%), medial orbital wall (anterior, 72%, posterior, 72%) and ethmoid-maxillary plate (64%). The false positive diagnosis was as follows: orbital floor (anterior only, 13%), medial orbital wall (anterior only, 7%) and ethmoid-maxillary plate (11%). The false negative diagnosis was as follows: orbital floor (anterior, 9%, posterior, 10%), medial orbital wall (anterior, 21%, posterior, 28%) and ethmoid-maxillary plate (21%). The results were compared with those of others in the past. (author)
Hara, Yasuo
1975-01-01
Peripheral orbit model, in which an incoming hadron is assumed to revolve in a peripheral orbit around a target hadron, is discussed. The non-diffractive parts of two-body reaction amplitudes of hadrons are expressed in terms of the radius, width an absorptivity of the orbit. The radius of the orbit is about 1 fm and the width of the orbit is determined by the range of the interaction between the hadrons. The model reproduces all available experimental data on differential cross-sections and polarizations of $K^{-}p\\to K^{-}p$ and $\\bar K^{\\circ}n$ reactions for all angles successfully. This contribution is not included in the proceedings since it will appear in Progress of Theoretical Physics Vol. 51 (1974) No 2. Any person interested in the subject may apply for reprints to the author.
Closed orbit related problems: Correction, feedback, and analysis
International Nuclear Information System (INIS)
Bozoki, E.S.
1995-01-01
Orbit correction - moving the orbit to a desired orbit, orbit stability - keeping the orbit on the desired orbit using feedback to filter out unwanted noise, and orbit analysis - to learn more about the model of the machine, are strongly interrelated. They are the three facets of the same problem. The better one knows the model of the machine, the better the predictions that can be made on the behavior of the machine (inverse modeling) and the more accurately one can control the machine. On the other hand, one of the tools to learn more about the machine (modeling) is to study and analyze the orbit response to open-quotes kicks.close quotes
International Nuclear Information System (INIS)
Rome, J.A.; Peng, Y.K.M.
1978-09-01
Guiding center orbits in noncircular axisymmetric tokamak plasmas are studied in the constants of motion (COM) space of (v, zeta, psi/sub m/). Here, v is the particle speed, zeta is the pitch angle with respect to the parallel equilibrium current, J/sub parallels/, and psi/sub m/ is the maximum value of the poloidal flux function (increasing from the magnetic axis) along the guiding center orbit. Two D-shaped equilibria in a flux-conserving tokamak having β's of 1.3% and 7.7% are used as examples. In this space, each confined orbit corresponds to one and only one point and different types of orbits (e.g., circulating, trapped, stagnation and pinch orbits) are represented by separate regions or surfaces in the space. It is also shown that the existence of an absolute minimum B in the higher β (7.7%) equilibrium results in a dramatically different orbit topology from that of the lower β case. The differences indicate the confinement of additional high energy (v → c, within the guiding center approximation) trapped, co- and countercirculating particles whose orbit psi/sub m/ falls within the absolute B well
Harmonically excited orbital variations
International Nuclear Information System (INIS)
Morgan, T.
1985-01-01
Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs
Zhang, Yunlin; Liu, Xiaohan; Osburn, Christopher L.; Wang, Mingzhu; Qin, Boqiang; Zhou, Yongqiang
2013-01-01
CDOM biogeochemical cycle is driven by several physical and biological processes such as river input, biogeneration and photobleaching that act as primary sinks and sources of CDOM. Watershed-derived allochthonous (WDA) and phytoplankton-derived autochthonous (PDA) CDOM were exposed to 9 days of natural solar radiation to assess the photobleaching response of different CDOM sources, using absorption and fluorescence (excitation-emission matrix) spectroscopy. Our results showed a marked decrease in total dissolved nitrogen (TDN) concentration under natural sunlight exposure for both WDA and PDA CDOM, indicating photoproduction of ammonium from TDN. In contrast, photobleaching caused a marked increase in total dissolved phosphorus (TDP) concentration for both WDA and PDA CDOM. Thus TDN∶TDP ratios decreased significantly both for WDA and PDA CDOM, which partially explained the seasonal dynamic of TDN∶TDP ratio in Lake Taihu. Photobleaching rate of CDOM absorption a(254), was 0.032 m/MJ for WDA CDOM and 0.051 m/MJ for PDA CDOM from days 0–9, indicating that phototransformations were initially more rapid for the newly produced CDOM from phytoplankton than for the river CDOM. Extrapolation of these values to the field indicated that 3.9%–5.1% CDOM at the water surface was photobleached and mineralized every day in summer in Lake Taihu. Photobleaching caused the increase of spectral slope, spectral slope ratio and molecular size, indicating the CDOM mean molecular weight decrease which was favorable to further microbial degradation of mineralization. Three fluorescent components were validated in parallel factor analysis models calculated separately for WDA and PDA CDOM. Our study suggests that the humic-like fluorescence materials could be rapidly and easily photobleached for WDA and PDA CDOM, but the protein-like fluorescence materials was not photobleached and even increased from the transformation of the humic-like fluorescence substance to the protein
International Nuclear Information System (INIS)
Boschi Oyhenart, J.; Tenyi, A.; Boschi Pau, J.
2002-01-01
Orbital varices are venous malformations produced by an abnormal dilatation of one or more orbital veins, probably associated with congenital weakness of the vascular wall. They are rare lesions, usually occurring in young patients, that produce intermittent proptosis related to the increase in the systemic venous pressure. The presence of hemorrhage or thrombosis is associated with rapid development of proptosis, pain and decreased ocular motility. We report the cases of two adult patients with orbital varices complicated by thrombosis in whom the diagnosis was based on computed tomography. The ultrasound and magnetic resonance findings are also discussed. (Author) 16 refs
Aiyub, Shereen; Chan, Wengonn; Szetu, John; Sullivan, Laurence J; Pater, John; Cooper, Peter; Selva, Dinesh
2013-12-01
We present a case of mature congenital orbital teratoma managed with lid-sparing exenteration and dermis fat graft. This is a case report on the management of congenital orbital teratoma. A full-term baby was born in Fiji with prolapsed right globe which was surrounded by a nonpulsatile, cystic mass. Clinical and imaging features were consistent with congenital orbital teratoma. Due to limited surgical expertise, the patient was transferred to Adelaide, Australia for further management. The patient underwent a lid-sparing exenteration with frozen section control of the apical margin. A dermis fat graft from the groin was placed beneath the lid skin to provide volume. Histopathology revealed mature tissues from each of the three germ cell layers which confirmed the diagnosis of mature teratoma. We describe the successful use of demis fat graft in socket reconstruction following lid-sparing exenteration for congenital orbital teratoma.
Directory of Open Access Journals (Sweden)
Shereen Aiyub
2013-01-01
Full Text Available We present a case of mature congenital orbital teratoma managed with lid-sparing exenteration and dermis fat graft. This is a case report on the management of congenital orbital teratoma. A full-term baby was born in Fiji with prolapsed right globe which was surrounded by a nonpulsatile, cystic mass. Clinical and imaging features were consistent with congenital orbital teratoma. Due to limited surgical expertise, the patient was transferred to Adelaide, Australia for further management. The patient underwent a lid-sparing exenteration with frozen section control of the apical margin. A dermis fat graft from the groin was placed beneath the lid skin to provide volume. Histopathology revealed mature tissues from each of the three germ cell layers which confirmed the diagnosis of mature teratoma. We describe the successful use of demis fat graft in socket reconstruction following lid-sparing exenteration for congenital orbital teratoma.
Chanel, M; Rumolo, G; Tomás, R; CERN. Geneva. AB Department
2008-01-01
ï»¿At the end of the 2007 run, orbit measurements were carried out in the 4 rings of the PS Booster (PSB) for different working points and beam energies. The aim of these measurements was to provide the necessary input data for a PSB realignment campaign during the 2007/2008 shutdown. Currently, only very few corrector magnets can be operated reliably in the PSB; therefore the orbit correction has to be achieved by displacing (horizontally and vertically) and/or tilting some of the defocusing quadrupoles (QDs). In this report we first describe the orbit measurements, followed by a detailed explanation of the orbit correction strategy. Results and conclusions are presented in the last section.
Weights assessment for orbit-on-demand vehicles
Macconochie, I. O.; Martin, J. A.; Breiner, C. A.; Cerro, J. A.
1985-01-01
Future manned, reusable earth-to-orbit vehicles may be required to reach orbit within hours or even minutes of a mission decision. A study has been conducted to consider vehicles with such a capability. In the initial phase of the study, 11 vehicles were sized for deployment of 5000 lbs to a polar orbit. From this matrix, two of the most promising concepts were resized for a modified mission and payload. A key feature of the study was the use of consistent mass estimating techniques for a broad range of concepts, allowing direct comparisons of sizes and weights.
Directory of Open Access Journals (Sweden)
Anatoliy Klimyk
2007-02-01
Full Text Available In the paper, properties of antisymmetric orbit functions are reviewed and further developed. Antisymmetric orbit functions on the Euclidean space $E_n$ are antisymmetrized exponential functions. Antisymmetrization is fulfilled by a Weyl group, corresponding to a Coxeter-Dynkin diagram. Properties of such functions are described. These functions are closely related to irreducible characters of a compact semisimple Lie group $G$ of rank $n$. Up to a sign, values of antisymmetric orbit functions are repeated on copies of the fundamental domain $F$ of the affine Weyl group (determined by the initial Weyl group in the entire Euclidean space $E_n$. Antisymmetric orbit functions are solutions of the corresponding Laplace equation in $E_n$, vanishing on the boundary of the fundamental domain $F$. Antisymmetric orbit functions determine a so-called antisymmetrized Fourier transform which is closely related to expansions of central functions in characters of irreducible representations of the group $G$. They also determine a transform on a finite set of points of $F$ (the discrete antisymmetric orbit function transform. Symmetric and antisymmetric multivariate exponential, sine and cosine discrete transforms are given.
International Nuclear Information System (INIS)
Anon.
1991-01-01
Critically aligned experiments are sensitive to small changes in the electron beam orbit. At the NSLS storage rings, the electron beam and photon beam motions have been monitored over the past several years. In the survey conducted in 1986 by the NSLS Users Executive Committee, experimenters requested the vertical beam position variation and the vertical angle variation, within a given fill, remain within 10 μm and 10 μr, respectively. This requires improvement in the beam stability by about one order of magnitude. At the NSLS and SSRL storage rings, the beam that is originally centered on the position monitor by a dc orbit correction is observed to have two kinds of motion: a dc drift over a storage period of several hours and a beam bounce about its nominal position. These motions are a result of the equilibrium orbit not being held perfectly stable due to time-varying errors introduced into the magnetic guide field by power supplies, mechanical vibration of the magnets, cooling water temperature variations, etc. The approach to orbit stabilization includes (1) identifying and suppressing as many noise sources on the machine as possible, (2) correcting the beam position globally (see Section 6) by controlling a number of correctors around the circumference of the machine, and (3) correcting the beam position and angle at a given source location by position feedback using local detectors and local orbit bumps. The third approach, called Local Orbit Feedback will be discussed in this section
Single-particle Glauber matrix elements
International Nuclear Information System (INIS)
Oset, E.; Strottman, D.
1983-01-01
The single-particle matrix elements of the Glauber profile function are tabulated for harmonic oscillator single-particle wave functions. The tables are presented in such a manner as to be applicable if the hadron--nucleon elementary scattering amplitude is specified by either a partial wave expansion or a Gaussian in momentum transfer squared. The table is complete through the 1 g/sub 9/2/ orbital and contains entries for the 3s/sub 1/2/ orbital for use if realistic wave functions are expanded in terms of harmonic oscillator functions
Multiscale Modeling of Ceramic Matrix Composites
Bednarcyk, Brett A.; Mital, Subodh K.; Pineda, Evan J.; Arnold, Steven M.
2015-01-01
Results of multiscale modeling simulations of the nonlinear response of SiC/SiC ceramic matrix composites are reported, wherein the microstructure of the ceramic matrix is captured. This micro scale architecture, which contains free Si material as well as the SiC ceramic, is responsible for residual stresses that play an important role in the subsequent thermo-mechanical behavior of the SiC/SiC composite. Using the novel Multiscale Generalized Method of Cells recursive micromechanics theory, the microstructure of the matrix, as well as the microstructure of the composite (fiber and matrix) can be captured.
International Nuclear Information System (INIS)
Sudarshan, K.; Tripathi, R.; Nair, A.G.C.; Acharya, R.; Reddy, A.V.R.; Goswami, A.
2005-01-01
A simple method using an internal standard is proposed to correct for the self-shielding effect of B, Cd and Gd in a matrix. This would increase the linear dynamic range of PGNAA in analyzing samples containing these elements. The method is validated by analyzing synthetic samples containing large amounts of B, Cd, Hg and Gd, the elements having high neutron absorption cross-section, in aqueous solutions and solid forms. A simple Monte-Carlo simulation to find the extent of self-shielding in the matrix is presented. The method is applied to the analysis of titanium boride alloy containing large amount of boron. The satisfactory results obtained showed the efficacy of the method of correcting for the self-shielding effects in the sample
Polarized atomic orbitals for linear scaling methods
Berghold, Gerd; Parrinello, Michele; Hutter, Jürg
2002-02-01
We present a modified version of the polarized atomic orbital (PAO) method [M. S. Lee and M. Head-Gordon, J. Chem. Phys. 107, 9085 (1997)] to construct minimal basis sets optimized in the molecular environment. The minimal basis set derives its flexibility from the fact that it is formed as a linear combination of a larger set of atomic orbitals. This approach significantly reduces the number of independent variables to be determined during a calculation, while retaining most of the essential chemistry resulting from the admixture of higher angular momentum functions. Furthermore, we combine the PAO method with linear scaling algorithms. We use the Chebyshev polynomial expansion method, the conjugate gradient density matrix search, and the canonical purification of the density matrix. The combined scheme overcomes one of the major drawbacks of standard approaches for large nonorthogonal basis sets, namely numerical instabilities resulting from ill-conditioned overlap matrices. We find that the condition number of the PAO overlap matrix is independent from the condition number of the underlying extended basis set, and consequently no numerical instabilities are encountered. Various applications are shown to confirm this conclusion and to compare the performance of the PAO method with extended basis-set calculations.
Directory of Open Access Journals (Sweden)
Jiri Patera
2008-01-01
Full Text Available We review and further develop the theory of $E$-orbit functions. They are functions on the Euclidean space $E_n$ obtained from the multivariate exponential function by symmetrization by means of an even part $W_{e}$ of a Weyl group $W$, corresponding to a Coxeter-Dynkin diagram. Properties of such functions are described. They are closely related to symmetric and antisymmetric orbit functions which are received from exponential functions by symmetrization and antisymmetrization procedure by means of a Weyl group $W$. The $E$-orbit functions, determined by integral parameters, are invariant withrespect to even part $W^{aff}_{e}$ of the affine Weyl group corresponding to $W$. The $E$-orbit functions determine a symmetrized Fourier transform, where these functions serve as a kernel of the transform. They also determine a transform on a finite set of points of the fundamental domain $F^{e}$ of the group $W^{aff}_{e}$ (the discrete $E$-orbit function transform.
Basanta, I; Sevillano, C; Álvarez, M D
2015-09-01
A case is presented of an 85 year-old Caucasian female with lymphoma that recurred in the orbit (secondary ocular adnexal lymphoma). The orbital tumour was a diffuse large B-cell lymphoma according to the REAL classification (Revised European-American Lymphoma Classification). Orbital lymphomas are predominantly B-cell proliferations of a variety of histological types, and most are low-grade tumours. Patients are usually middle-aged or elderly, and it is slightly more common in women. A palpable mass, proptosis and blepharoptosis are the most common signs of presentation. Copyright © 2011 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.
Large orbit neoclassical transport
International Nuclear Information System (INIS)
Lin, Z.; Tang, W.M.; Lee, W.W.
1997-01-01
Neoclassical transport in the presence of large ion orbits is investigated. The study is motivated by the recent experimental results that ion thermal transport levels in enhanced confinement tokamak plasmas fall below the open-quotes irreducible minimum levelclose quotes predicted by standard neoclassical theory. This apparent contradiction is resolved in the present analysis by relaxing the basic neoclassical assumption that the ions orbital excursions are much smaller than the local toroidal minor radius and the equilibrium scale lengths of the system. Analytical and simulation results are in agreement with trends from experiments. The development of a general formalism for neoclassical transport theory with finite orbit width is also discussed. copyright 1997 American Institute of Physics
The nuclear spin-orbit coupling
International Nuclear Information System (INIS)
Bell, J.S.; Skyrme, T.H.R.
1994-01-01
Analysis of the nucleon-nucleon scattering around 100 MeV has determined the spin-orbit coupling part of the two-body scattering matrix at that energy, and a reasonable extrapolation to lower energies is possible. This scattering amplitude has been used, in the spirit of Brueckner's nuclear model, to estimate the resultant single-body spin-orbit coupling for a single nucleon interacting with a large nucleus. This resultant potential has a radial dependence approximately proportional to r -1 d ρ /dr, and with a magnitude in good agreement with that required to explain the doublet splittings in nuclei and the polarization of nucleons scattered elastically off nuclei. (author). 14 refs, 2 figs
International Nuclear Information System (INIS)
Hoeschen, W.
2003-01-01
The TIG (Tungsten-inert gas) orbital welding technique is applied in all areas of pipe welding. The process is mainly used for austenitic and ferritic materials but also for materials like aluminium, nickel, and titanium alloys are commonly welded according to this technique. Thin-walled as well as thick-walled pipes are welded economically. The application of orbital welding is of particular interest in the area of maintenance of thick-walled pipes that is described in this article. (orig.) [de
Linear orbit parameters for the exact equations of motion
International Nuclear Information System (INIS)
Parzen, G.
1995-01-01
This paper defines the beta function and other linear orbit parameters using the exact equations of motion. The β, α and ψ functions are redefined using the exact equations. Expressions are found for the transfer matrix and the emittance. The differential equations for η = x/β 1/2 is found. New relationships between α, β, ψ and ν are derived
Radiotherapy of lymphoid diseases of the orbit
International Nuclear Information System (INIS)
Austin-Seymour, M.M.; Donaldson, S.S.; Egbert, P.R.; McDougall, I.R.; Kriss, J.P.
1985-01-01
Thirty-two patients with orbital pseudotumor (18), reactive lymphoid hyperplasia (2), atypical lymphoid infiltrate (4) or malignant lymphoma (8) were treated in the Division of Radiation Therapy at Stanford University between January 1973 and May 1983. Of the 20 patients with pseudotumor or reactive lymphoid hyperplasia, 10 had unilateral lesions and 10 had bilateral lesions. Biopsy samples were obtained in 15 patients; in five patients with bilateral disease the diagnosis was made on the basis of computed tomography (CT) and clinical findings. The majority of patients were referred because of disease refractory to treatment with corticosteroids. The patients were given a mean dose of 2360 rad using complex, individualized megavoltage techniques including lens shielding. Radiotherapy was well tolerated with no significant acute or late complications. Fifteen patients had complete resolution of symptoms after treatment; five had continued symptoms. Of the 12 patients with malignant lymphoma or atypical lymphoid infiltrate, four had systemic lymphoma with orbital involvement and eight had orbital involvement only. A mean dose of 3625 rad was delivered to the orbit only. Most of the patients received complex megavoltage treatment using bolus. All patients in this group had a complete response and local control. Two patients developed cataracts. Carefullly planned orbital radiotherapy provides local control without symptomatic sequelae for orbital masses ranging from pseudotumor to malignant lymphoma
Directory of Open Access Journals (Sweden)
Kyu-Hong Choi
1990-06-01
Full Text Available The osculating orbital elements include the mean, secular, long period, and short period terms. The iterative algorithm used for conversion of osculating orbital elements to mean orbital elements is described. The mean orbital elements of Wc, Ws, and L are obtained.
Extracellular matrix component signaling in cancer
DEFF Research Database (Denmark)
Multhaupt, Hinke A. B.; Leitinger, Birgit; Gullberg, Donald
2016-01-01
Cell responses to the extracellular matrix depend on specific signaling events. These are important from early development, through differentiation and tissue homeostasis, immune surveillance, and disease pathogenesis. Signaling not only regulates cell adhesion cytoskeletal organization and motil...... as well as matrix constitution and protein crosslinking. Here we summarize roles of the three major matrix receptor types, with emphasis on how they function in tumor progression. [on SciFinder(R)]...
Directory of Open Access Journals (Sweden)
Dezerega Andrea
2012-03-01
Full Text Available Abstract Background Oxidative stress and matrix metalloproteinases -9 and -2 are involved in periodontal breakdown, whereas gingival crevicular fluid has been reported to reflect apical status. The aim of this study was to characterize oxidant balance and activity levels of MMP -2 and -9 in apical lesions and healthy periodontal ligament; and second, to determine whether potential changes in oxidant balance were reflected in gingival crevicular fluid from asymptomatic apical periodontitis (AAP-affected teeth at baseline and after endodontic treatment. Methods Patients with clinical diagnosis of AAP and healthy volunteers having indication of tooth extraction were recruited. Apical lesions and healthy periodontal ligaments, respectively, were homogenized or processed to obtain histological tissue sections. Matrix metalloproteinase -9 and -2 levels and/or activity were analyzed by Immunowestern blot, zymography and consecutive densitometric analysis, and their tissue localization was confirmed by immunohistochemistry. A second group of patients with AAP and indication of endodontic treatment was recruited. Gingival crevicular fluid was extracted from AAP-affected teeth at baseline, after endodontic treatment and healthy contralateral teeth. Total oxidant and antioxidant status were determined in homogenized tissue and GCF samples. Statistical analysis was performed using STATA v10 software with unpaired t test, Mann-Whitney test and Spearman's correlation. Results Activity of MMP-2 and MMP-9 along with oxidant status were higher in apical lesions (p Conclusions Apical lesions display an oxidant imbalance along with increased activity of matrix metalloproteinase-2 and -9 and might contribute to AAP progression. Oxidant imbalance can also be reflected in GCF from AAP-affected teeth and was restored to normal levels after conservative endodontic treatment. These mediators might be useful as potential biomarkers for chair-side complementary diagnostic
Dezerega, Andrea; Madrid, Sonia; Mundi, Verónica; Valenzuela, María A; Garrido, Mauricio; Paredes, Rodolfo; García-Sesnich, Jocelyn; Ortega, Ana V; Gamonal, Jorge; Hernández, Marcela
2012-03-21
Oxidative stress and matrix metalloproteinases -9 and -2 are involved in periodontal breakdown, whereas gingival crevicular fluid has been reported to reflect apical status. The aim of this study was to characterize oxidant balance and activity levels of MMP -2 and -9 in apical lesions and healthy periodontal ligament; and second, to determine whether potential changes in oxidant balance were reflected in gingival crevicular fluid from asymptomatic apical periodontitis (AAP)-affected teeth at baseline and after endodontic treatment. Patients with clinical diagnosis of AAP and healthy volunteers having indication of tooth extraction were recruited. Apical lesions and healthy periodontal ligaments, respectively, were homogenized or processed to obtain histological tissue sections. Matrix metalloproteinase -9 and -2 levels and/or activity were analyzed by Immunowestern blot, zymography and consecutive densitometric analysis, and their tissue localization was confirmed by immunohistochemistry. A second group of patients with AAP and indication of endodontic treatment was recruited. Gingival crevicular fluid was extracted from AAP-affected teeth at baseline, after endodontic treatment and healthy contralateral teeth. Total oxidant and antioxidant status were determined in homogenized tissue and GCF samples. Statistical analysis was performed using STATA v10 software with unpaired t test, Mann-Whitney test and Spearman's correlation. Activity of MMP-2 and MMP-9 along with oxidant status were higher in apical lesions (p Apical lesions display an oxidant imbalance along with increased activity of matrix metalloproteinase-2 and -9 and might contribute to AAP progression. Oxidant imbalance can also be reflected in GCF from AAP-affected teeth and was restored to normal levels after conservative endodontic treatment. These mediators might be useful as potential biomarkers for chair-side complementary diagnostic of apical status in GCF.
Critical homoclinic orbits lead to snap-back repellers
International Nuclear Information System (INIS)
Gardini, Laura; Sushko, Iryna; Avrutin, Viktor; Schanz, Michael
2011-01-01
Highlights: → We consider critical homoclinic orbits in continuous and discontinuous maps. → Unbounded homoclinic orbits in maps on unbounded domains are considered as well. → We show that a snapback-repeller (SBR) with a non-critical homoclinic orbit implies chaos. → We show also that a SBR with a critical homoclinic orbit may or may not imply chaos. - Abstract: When nondegenerate homoclinic orbits to an expanding fixed point of a map f:X→X,X subset or equal R n , exist, the point is called a snap-back repeller. It is known that the relevance of a snap-back repeller (in its original definition) is due to the fact that it implies the existence of an invariant set on which the map is chaotic. However, when does the first homoclinic orbit appear? When can other homoclinic explosions, i.e., appearance of infinitely many new homoclinic orbits, occur? As noticed by many authors, these problems are still open. In this work we characterize these bifurcations, for any kind of map, smooth or piecewise smooth, continuous or discontinuous, defined in a bounded or unbounded closed set. We define a noncritical homoclinic orbit and a homoclinic orbit of an expanding fixed point is structurally stable iff it is noncritical. That is, only critical homoclinic orbits are responsible for the homoclinic explosions. The possible kinds of critical homoclinic orbits will be also investigated, as well as their dynamic role.
Efficiency criterion for teleportation via channel matrix, measurement matrix and collapsed matrix
Directory of Open Access Journals (Sweden)
Xin-Wei Zha
Full Text Available In this paper, three kinds of coefficient matrixes (channel matrix, measurement matrix, collapsed matrix associated with the pure state for teleportation are presented, the general relation among channel matrix, measurement matrix and collapsed matrix is obtained. In addition, a criterion for judging whether a state can be teleported successfully is given, depending on the relation between the number of parameter of an unknown state and the rank of the collapsed matrix. Keywords: Channel matrix, Measurement matrix, Collapsed matrix, Teleportation
Nakayama, Koh
2013-01-01
Responses to low levels of oxygen (hypoxia) are essential to maintain homeostasis. During the hypoxic response, gene expression is altered by various transcription factors. The transcription factor, hypoxia-inducible factor (HIF), plays a central role in the hypoxic response. The α subunit of HIF, which is actively degraded during normoxia, becomes stabilized during hypoxia, which leads to HIF activation. A microarray analysis of HeLa cells showed that expression of matrix metalloproteinase 1 (MMP1) was markedly induced during prolonged hypoxia. CREB and NF-κB binding sites were identified in the MMP1 promoter region between 1945 and 1896 nucleotides upstream of the transcription start site. Assays with luciferase reporters demonstrated that HIF activity was induced during the early phase of hypoxia, whereas CREB and NF-κB were activated during the later (prolonged) phase. Depletion of CREB and/or NF-κB reduced MMP1 induction during prolonged hypoxia both at the mRNA and protein levels. A chromatin immunoprecipitation assay demonstrated binding of CREB and NF-κB to the MMP1 promoter. Finally, cell migration and invasion on a collagen matrix and pulmonary metastasis in nude mice were inhibited after depletion of CREB and NF-κB in MDA-MB-231 cells. Taken together, these results suggest that the cooperative action of CREB and NF-κB plays an important role to induce MMP1 expression during prolonged hypoxia and regulates cell migration and invasion in cancer cells. PMID:23775082
Directory of Open Access Journals (Sweden)
Ravi N Vellanki
Full Text Available OASIS is a transcription factor similar to ATF6 that is activated by endoplasmic reticulum stress. In this study we investigated the expression of OASIS in human glioma cell lines and the effect of OASIS knock-down on the ER stress response and cell migration. OASIS mRNA was detected in three distinct glioma cell lines (U373, A172 and U87 and expression levels were increased upon treatment with ER stress-inducing compounds in the U373 and U87 lines. OASIS protein, which is glycosylated on Asn-513, was detected in the U373 and U87 glioma lines at low levels in control cells and protein expression was induced by ER stress. Knock-down of OASIS in human glioma cell lines resulted in an attenuated unfolded protein response to ER stress (reduced GRP78/BiP and GRP94 induction and decreased expression of chondroitin sulfate proteoglycan extracellular matrix proteins, but induction of the collagen gene Col1a1 was unaffected. Cells in which OASIS was knocked-down exhibited altered cell morphology and reduced cell migration. These results suggest that OASIS is important for the ER stress response and maintenance of some extracellular matrix proteins in human glioma cells.
Effects of LDEF flight exposure on selected polymer matrix resin composite materials
Slemp, Wayne S.; Young, Philip R.; Witte, William G., Jr.; Shen, James Y.
1992-01-01
The characterization of selected graphite fiber reinforced epoxy (934 and 5208) and polysulfone (P1700) matrix resin composites materials which received over five years and nine months of exposure to the low earth orbit (LEO) environment in experiment AO134 on the Long Duration Exposure Facility is reported. The changes in mechanical properties of ultimate tensile strength and tensile modulus for exposed flight specimens are compared to the three sets of control specimens. Marked changes in surface appearance are discussed, and resin loss is reported. The chemical characterization including infrared, thermal, and selected solution property measurements showed that the molecular structure of the polymetric matrix had not changed significantly in response to this exposure.
Integrins and extracellular matrix in mechanotransduction
Directory of Open Access Journals (Sweden)
Ramage L
2011-12-01
Full Text Available Lindsay RamageQueen’s Medical Research Institute, University of Edinburgh, Edinburgh, UKAbstract: Integrins are a family of cell surface receptors which mediate cell–matrix and cell–cell adhesions. Among other functions they provide an important mechanical link between the cells external and intracellular environments while the adhesions that they form also have critical roles in cellular signal-transduction. Cell–matrix contacts occur at zones in the cell surface where adhesion receptors cluster and when activated the receptors bind to ligands in the extracellular matrix. The extracellular matrix surrounds the cells of tissues and forms the structural support of tissue which is particularly important in connective tissues. Cells attach to the extracellular matrix through specific cell-surface receptors and molecules including integrins and transmembrane proteoglycans. Integrins work alongside other proteins such as cadherins, immunoglobulin superfamily cell adhesion molecules, selectins, and syndecans to mediate cell–cell and cell–matrix interactions and communication. Activation of adhesion receptors triggers the formation of matrix contacts in which bound matrix components, adhesion receptors, and associated intracellular cytoskeletal and signaling molecules form large functional, localized multiprotein complexes. Cell–matrix contacts are important in a variety of different cell and tissue properties including embryonic development, inflammatory responses, wound healing, and adult tissue homeostasis. This review summarizes the roles and functions of integrins and extracellular matrix proteins in mechanotransduction.Keywords: ligand binding, α subunit, ß subunit, focal adhesion, cell differentiation, mechanical loading, cell–matrix interaction
Extended biorthogonal matrix polynomials
Directory of Open Access Journals (Sweden)
Ayman Shehata
2017-01-01
Full Text Available The pair of biorthogonal matrix polynomials for commutative matrices were first introduced by Varma and Tasdelen in [22]. The main aim of this paper is to extend the properties of the pair of biorthogonal matrix polynomials of Varma and Tasdelen and certain generating matrix functions, finite series, some matrix recurrence relations, several important properties of matrix differential recurrence relations, biorthogonality relations and matrix differential equation for the pair of biorthogonal matrix polynomials J(A,B n (x, k and K(A,B n (x, k are discussed. For the matrix polynomials J(A,B n (x, k, various families of bilinear and bilateral generating matrix functions are constructed in the sequel.
Matrix completion by deep matrix factorization.
Fan, Jicong; Cheng, Jieyu
2018-02-01
Conventional methods of matrix completion are linear methods that are not effective in handling data of nonlinear structures. Recently a few researchers attempted to incorporate nonlinear techniques into matrix completion but there still exists considerable limitations. In this paper, a novel method called deep matrix factorization (DMF) is proposed for nonlinear matrix completion. Different from conventional matrix completion methods that are based on linear latent variable models, DMF is on the basis of a nonlinear latent variable model. DMF is formulated as a deep-structure neural network, in which the inputs are the low-dimensional unknown latent variables and the outputs are the partially observed variables. In DMF, the inputs and the parameters of the multilayer neural network are simultaneously optimized to minimize the reconstruction errors for the observed entries. Then the missing entries can be readily recovered by propagating the latent variables to the output layer. DMF is compared with state-of-the-art methods of linear and nonlinear matrix completion in the tasks of toy matrix completion, image inpainting and collaborative filtering. The experimental results verify that DMF is able to provide higher matrix completion accuracy than existing methods do and DMF is applicable to large matrices. Copyright © 2017 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Harcourt, R.D.
1987-01-01
Bohr orbit theory is used to calculate energies for the 1S, 2P, 3D, 4F and 5G states of the helium muonic atom, when the muon is excited. These energies are close to those which have been calculated variationally by Huang (1977, Phys. Rev. A 15 1832-8). (author)
Directory of Open Access Journals (Sweden)
RS Nirmal
2013-11-01
Full Text Available Stem cell based tissue engineering has emerged as a promising strategy for articular cartilage regeneration. Foetal derived mesenchymal stem cells (MSCs with their ease of availability, pluripotency and high expansion potential have been demonstrated to be an attractive cell source over adult MSCs. However, there is a need for optimisation of chondrogenic signals to direct the differentiation of these multipotent MSCs to chondrogenic lineage. In this study we have demonstrated the in vitro chondrogenesis of human umbilical cord matrix MSCs in three dimensional PVA-PCL (polyvinyl alcohol-polycaprolactone scaffolds in the presence of the individual growth factors TGFβ1, TGFβ3, IGF, BMP2 and their combination with BMP2. Gene expression, histology and immunohistology were evaluated after 28 d culture. The induced cells showed the feature of chondrocytes in their morphology and expression of typical chondrogenic extracellular matrix molecules. Moreover, the real-time PCR assay has shown the expression of gene markers of chondrogenesis, SOX9, collagen type II and aggrecan. The expression of collagen type I and collagen type X was also evaluated. This study has demonstrated the successful chondrogenic induction of human umbilical cord MSCs in 3D scaffolds. Interestingly, the growth factor combination of TGF-β3 and BMP-2 was found to be more effective for chondrogenesis as shown by the real-time PCR studies. The findings of this study suggest the importance of using growth factor combinations for successful chondrogenic differentiation of umbilical cord MSCs.
Energy Technology Data Exchange (ETDEWEB)
Priyadarshi, Devinder [DAV Institute of Engineering and Technology, Jalandhar (India); Sharma, Rajesh Kumar [Institute of Technology, Hamirpur (India)
2016-03-15
Aluminium matrix composites (AMCs) now hold a significant share of raw materials in many applications. It is of prime importance to study the machinability of such composites so as to enhance their applicability. Sufficient work has been done for studying the machining of AMCs with particle reinforcements of micron range. This paper presents the study of AMCs with particle reinforcement of under micron range i.e. nanoparticles. This paper brings out the results of an experimental investigation of type and weight percent of nanoparticles on the tangential cutting force during turning operation. SiC, Gr and SiC-Gr (in equal proportions) were used with Al-6061 alloy as the matrix phase. The results indicate that composites with SiC require greater cutting force followed by hybrid and then Gr. Increase in the weight percent also significantly affected the magnitude of cutting force. RSM was used first to design and analyze the experiments and then to optimize the turning process and obtain optimal conditions of weight and type of reinforcements for turning operation.
Ngwuluka, Ndidi C; Choonara, Yahya E; Kumar, Pradeep; du Toit, Lisa C; Khan, Riaz A; Pillay, Viness
2015-03-01
This study was undertaken in order to apply a synthesized interpolyelectrolyte complex (IPEC) of polymethacrylate and carboxymethylcellulose as a controlled release oral tablet matrix for the delivery of the model neuroactive drug levodopa. The IPEC (synthesized in Part I of this work) was characterized by techniques such as Fourier Transform Infra-Red (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC), Advanced DSC (ADSC), and Scanning Electron Microscopy (SEM). The tablet matrices were formulated and characterized for their drug delivery properties and in vitro drug release. FTIR confirmed the interaction between the two polymers. The IPEC composite generated tablet matrices with a hardness ranging from 19.152-27.590 N/mm and a matrix resilience ranging between 42 and 46%. An IPEC of polymethacrylate and carboxymethylcellulose was indeed an improvement on the inherent properties of the native polymers providing a biomaterial with the ability to release poorly soluble drugs such as levodopa at a constant rate over a prolonged period of time. © 2014 Wiley Periodicals, Inc.
Meteoroid Orbits from Observations
Campbell-Brown, Margaret
2018-04-01
Millions of orbits of meteoroids have been measured over the last few decades, and they comprise the largest sample of orbits of solar system bodies which exists. The orbits of these objects can shed light on the distribution and evolution of comets and asteroids in near-Earth space (e.g. Neslusan et al. 2016). If orbits can be measured at sufficiently high resolution, individual meteoroids can be traced back to their parent bodies and, in principle, even to their ejection time (Rudawska et al. 2012). Orbits can be measured with multi-station optical observations or with radar observations.The most fundamental measured quantities are the speed of the meteor and the two angles of the radiant, or point in the sky from which the meteor appears to come. There are many methods used to determine these from observations, but not all produce the most accurate results (Egal et al. 2017). These three measured quantities, along with the time and location of the observation, are sufficient to obtain an orbit (see, e.g., Clark & Wiegert 2011), but the measurements must be corrected for the deceleration of the meteoroid in the atmosphere before it was detected, the rotation of the Earth, and the gravitational attraction of the Earth (including higher order moments if great precision is necessary).Once meteor orbits have been determined, studies of the age and origin of meteor showers (Bruzzone et al., 2015), the parent bodies of sporadic sources (Pokorny et al. 2014), and the dynamics of the meteoroid complex as a whole can be constrained.Bruzzone, J. S., Brown, P., Weryk, R., Campbell-Brown, M., 2015. MNRAS 446, 1625.Clark, D., Wiegert, P., 2011. M&PS 46, 1217.Egal, A., Gural, P., Vaubaillon, J., Colas, F., Thuillot, W., 2017. Icarus 294, 43.Neslusan, L., Vaubaillon, J., Hajdukova, M., 2016. A&A 589, id.A100.Pokorny, P., Vokrouhlicky, D., Nesvorny, D., Campbell-Brown, M., Brown, P., 2014. ApJ 789, id.25.Rudawska, R., Vaubaillon, J., Atreya, P., 2012. A&A 541, id.A2
Czech Academy of Sciences Publication Activity Database
Chlupáč, Jaroslav; Filová, Elena; Havlíková, Jana; Matějka, R.; Riedel, Tomáš; Houska, Milan; Brynda, Eduard; Pamula, E.; Rémy, M.; Bareille, R.; Fernandez, P.; Daculsi, R.; Bourget, Ch.; Bačáková, Lucie; Bordenave, L.
2014-01-01
Roč. 20, 15-16 (2014), s. 2253-2264 ISSN 2152-4947 R&D Projects: GA ČR(CZ) GAP108/10/1106; GA ČR(CZ) GAP108/11/1857; GA ČR(CZ) GA305/08/0108; GA ČR GAP205/12/1702; GA MŠk(CZ) EE2.3.30.0029; GA MŠk(CZ) ED1.1.00/02.0109; GA MZd(CZ) NT11270 Grant - others:GA MŠk(CZ) Barrande 2005-06-036-1 Institutional support: RVO:67985823 ; RVO:61389013 Keywords : atherosclerosis * endothelial cells * extracellular matrix proteins * tissue engineering Subject RIV: EI - Biotechnology ; Bionics; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 4.448, year: 2014
Mechnich, P.; Braue, W.; Schneider, H.; Koch, U.; Esser, B.; Gülhan, A.
2005-02-01
All-oxide ceramic matrix composites (CMCs) such as WHIPOXTM (wound highly porous oxide) exhibit excellent damage tolerance and thermal stability up to 1400°C. Due to their low density and thermal conductivity these new ceramic materials are considered promising candidates for thermal protection systems (TPS) of spacecrafts. The performance of WHIPOX-type CMCs was evaluated during reentry simulations in the L2K leg of the arc-heated LBK facility of DLR, Cologne. The application of reaction-bonded alumina (RBAO) coatings provides significant CMC surface protection and decreased gas permeability, which are key issues for reentry applications. Since emittance and catalycity of the RBAO-coatings limit the performance of CMCs in a reentry environment, binary SiC/RBAO coatings providing higher emittance and/or lower catalycity proved to be a promising approach.
DEFF Research Database (Denmark)
Petersen, Kaare Brandt; Pedersen, Michael Syskind
Matrix identities, relations and approximations. A desktop reference for quick overview of mathematics of matrices.......Matrix identities, relations and approximations. A desktop reference for quick overview of mathematics of matrices....
Local orbitals by minimizing powers of the orbital variance
DEFF Research Database (Denmark)
Jansik, Branislav; Høst, Stinne; Kristensen, Kasper
2011-01-01
's correlation consistent basis sets, it is seen that for larger penalties, the virtual orbitals become more local than the occupied ones. We also show that the local virtual HF orbitals are significantly more local than the redundant projected atomic orbitals, which often have been used to span the virtual...
Tailoring spin-orbit torque in diluted magnetic semiconductors
Li, Hang; Wang, Xuhui; Doǧan, Fatih; Manchon, Aurelien
2013-01-01
We study the spin orbit torque arising from an intrinsic linear Dresselhaus spin-orbit coupling in a single layer III-V diluted magnetic semiconductor. We investigate the transport properties and spin torque using the linear response theory, and we report here: (1) a strong correlation exists between the angular dependence of the torque and the anisotropy of the Fermi surface; (2) the spin orbit torque depends nonlinearly on the exchange coupling. Our findings suggest the possibility to tailor the spin orbit torque magnitude and angular dependence by structural design.
Tailoring spin-orbit torque in diluted magnetic semiconductors
Li, Hang
2013-05-16
We study the spin orbit torque arising from an intrinsic linear Dresselhaus spin-orbit coupling in a single layer III-V diluted magnetic semiconductor. We investigate the transport properties and spin torque using the linear response theory, and we report here: (1) a strong correlation exists between the angular dependence of the torque and the anisotropy of the Fermi surface; (2) the spin orbit torque depends nonlinearly on the exchange coupling. Our findings suggest the possibility to tailor the spin orbit torque magnitude and angular dependence by structural design.
Farooque, Mohammad; Yuh, Chao-Yi
1996-01-01
A carbonate fuel cell matrix comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles.
International Nuclear Information System (INIS)
Maddox, L.B.; McNeilly, G.S.
1979-08-01
GOC (General Orbit Code) is a versatile program which will perform a variety of calculations relevant to isochronous cyclotron design studies. In addition to the usual calculations of interest (e.g., equilibrium and accelerated orbits, focusing frequencies, field isochronization, etc.), GOC has a number of options to calculate injections with a charge change. GOC provides both printed and plotted output, and will follow groups of particles to allow determination of finite-beam properties. An interactive PDP-10 program called GIP, which prepares input data for GOC, is available. GIP is a very easy and convenient way to prepare complicated input data for GOC. Enclosed with this report are several microfiche containing source listings of GOC and other related routines and the printed output from a multiple-option GOC run
Matrix with Prescribed Eigenvectors
Ahmad, Faiz
2011-01-01
It is a routine matter for undergraduates to find eigenvalues and eigenvectors of a given matrix. But the converse problem of finding a matrix with prescribed eigenvalues and eigenvectors is rarely discussed in elementary texts on linear algebra. This problem is related to the "spectral" decomposition of a matrix and has important technical…
Indian Academy of Sciences (India)
Much of linear algebra is devoted to reducing a matrix (via similarity or unitary similarity) to another that has lots of zeros. The simplest such theorem is the Schur triangularization theorem. This says that every matrix is unitarily similar to an upper triangular matrix. Our aim here is to show that though it is very easy to prove it ...
Orbital debris: a technical assessment
National Research Council Canada - National Science Library
Committee on Space Debris, National Research Council
..., and other debris created as a byproduct of space operations. Orbital Debris examines the methods we can use to characterize orbital debris, estimates the magnitude of the debris population, and assesses the hazard that this population poses to spacecraft...
Fermi Surface of Sr_{2}RuO_{4}: Spin-Orbit and Anisotropic Coulomb Interaction Effects.
Zhang, Guoren; Gorelov, Evgeny; Sarvestani, Esmaeel; Pavarini, Eva
2016-03-11
The topology of the Fermi surface of Sr_{2}RuO_{4} is well described by local-density approximation calculations with spin-orbit interaction, but the relative size of its different sheets is not. By accounting for many-body effects via dynamical mean-field theory, we show that the standard isotropic Coulomb interaction alone worsens or does not correct this discrepancy. In order to reproduce experiments, it is essential to account for the Coulomb anisotropy. The latter is small but has strong effects; it competes with the Coulomb-enhanced spin-orbit coupling and the isotropic Coulomb term in determining the Fermi surface shape. Its effects are likely sizable in other correlated multiorbital systems. In addition, we find that the low-energy self-energy matrix-responsible for the reshaping of the Fermi surface-sizably differs from the static Hartree-Fock limit. Finally, we find a strong spin-orbital entanglement; this supports the view that the conventional description of Cooper pairs via factorized spin and orbital part might not apply to Sr_{2}RuO_{4}.
National Research Council Canada - National Science Library
Sarkar, Tapan
2000-01-01
.... The SEM poles are independent of the angle at which the transient response is recorded. The only difference between the various waveforms are that the residues at the various poles are of different magnitudes...
Energy Technology Data Exchange (ETDEWEB)
Baltazar R, A.; Vega C, H. R.; Ortiz R, J. M.; Solis S, L. O.; Castaneda M, R. [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Programa de Doctorado en Ingenieria y Tecnologia Aplicada, Av. Lopez Velarde s/n, 98000 Zacatecas, Zac. (Mexico); Soto B, T. G.; Medina C, D., E-mail: raigosa.antonio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Programa de Doctorado en Ciencias Basicas (Ciencias Nucleares), Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas, Zac. (Mexico)
2017-10-15
In the last three decades the uses of Monte Carlo methods, for the estimation of physical phenomena associated with the interaction of radiation with matter, have increased considerably. The reason is due to the increase in computing capabilities and the reduction of computer prices. Monte Carlo methods allow modeling and simulating real systems before their construction, saving time and costs. The interaction mechanisms between neutrons and matter are diverse and range from elastic dispersion to nuclear fission; to facilitate the neutrons detection, is necessary to moderate them until reaching electronic equilibrium with the medium at standard conditions of pressure and temperature, in this state the total cross section of the {sup 3}He is large. The objective of the present work was to estimate the response matrix of a proportional detector of {sup 3}He using regular volumes of moderator through Monte Carlo methods. Neutron monoenergetic sources with energies of 10{sup -9} to 20 MeV and polyethylene moderators of different sizes were used. The calculations were made with the MCNP5 code; the number of stories for each detector-moderator combination was large enough to obtain errors less than 1.5%. We found that for small moderators the highest response is obtained for lower energy neutrons, when increasing the moderator dimension we observe that the response decreases for neutrons of lower energy and increases for higher energy neutrons. The total sum of the responses of each moderator allows obtaining a response close to a constant function. (Author)
Orbiter OMS and RCS technology
Boudreaux, R. A.
1982-01-01
Orbiter Orbital Maneuver Subsystem (OMS) and Reaction Control Subsystem (RCS) tankage has proved to be highly successful in shuttle flights on-orbit propellant transfer tests were done. Tank qualification tests along with flight demonstrations were carried out future uses of storable propellants are cited.
Directory of Open Access Journals (Sweden)
Youtao Gao
2016-01-01
Full Text Available The accuracy of autonomous orbit determination of Lagrangian navigation constellation will affect the navigation accuracy for the deep space probes. Because of the special dynamical characteristics of Lagrangian navigation satellite, the error caused by different estimation algorithm will cause totally different autonomous orbit determination accuracy. We apply the extended Kalman filter and the fading–memory filter to determinate the orbits of Lagrangian navigation satellites. The autonomous orbit determination errors are compared. The accuracy of autonomous orbit determination using fading-memory filter can improve 50% compared to the autonomous orbit determination accuracy using extended Kalman filter. We proposed an integrated Kalman fading filter to smooth the process of autonomous orbit determination and improve the accuracy of autonomous orbit determination. The square root extended Kalman filter is introduced to deal with the case of inaccurate initial error variance matrix. The simulations proved that the estimation method can affect the accuracy of autonomous orbit determination greatly.
Directory of Open Access Journals (Sweden)
Alessandra Apicella
Full Text Available In a current procedure for periodontal tissue regeneration, enamel matrix derivative (EMD, which is the active component, is mixed with a propylene glycol alginate (PGA gel carrier and applied directly to the periodontal defect. Exposure of EMD to physiological conditions then causes it to precipitate. However, environmental changes during manufacture and storage may result in modifications to the conformation of the EMD proteins, and eventually premature phase separation of the gel and a loss in therapeutic effectiveness. The present work relates to efforts to improve the stability of EMD-based formulations such as Emdogain™ through the incorporation of arginine, a well-known protein stabilizer, but one that to our knowledge has not so far been considered for this purpose. Representative EMD-buffer solutions with and without arginine were analyzed by 3D-dynamic light scattering, UV-Vis spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy at different acidic pH and temperatures, T, in order to simulate the effect of pH variations and thermal stress during manufacture and storage. The results provided evidence that arginine may indeed stabilize EMD against irreversible aggregation with respect to variations in pH and T under these conditions. Moreover, stopped-flow transmittance measurements indicated arginine addition not to suppress precipitation of EMD from either the buffers or the PGA gel carrier when the pH was raised to 7, a fundamental requirement for dental applications.
Wang, Feng-Wei; Cai, Mu-Yan; Mai, Shi-Juan; Chen, Jie-Wei; Bai, Hai-Yan; Li, Yan; Liao, Yi-Ji; Li, Chang-Peng; Tian, Xiao-Peng; Kung, Hsiang-Fu; Guan, Xin-Yuan; Xie, Dan
2014-08-30
Hepatocellular carcinoma (HCC) is a highly vascularized tumor with poor clinical outcome. Our previous work has shown that eukaryotic initiation factor 5A2 (EIF5A2) over-expression enhances HCC cell metastasis. In this study, EIF5A2 was identified to be an independent risk factor for poor disease-specific survival among HCC patients. Both in vitro and in vivo assays indicated that ablation of endogenous EIF5A2 inhibited tumor angiogenesis by reducing matrix metalloproteinase 2 (MMP-2) expression. Given that MMP-2 degrades collagen IV, a main component of the vascular basement membrane (BM), we subsequently investigated the effect of EIF5A2 on tumor vasculature remodeling using complementary approaches, including fluorescent immunostaining, transmission electron microscopy, tumor perfusion assays and tumor hypoxia assays. Taken together, our results indicate that EIF5A2 silencing increases tumor vessel wall continuity, increases blood perfusion and improves tumor oxygenation. Additionally, we found that ablation of EIF5A2 enhanced the chemosensitivity of HCC cells to 5-Fluorouracil (5-FU). Finally, we demonstrated that EIF5A2 might exert these functions by enhancing MMP-2 activity via activation of p38 MAPK and JNK/c-Jun pathways. This study highlights an important role of EIF5A2 in HCC tumor vessel remodeling and indicates that EIF5A2 represents a potential therapeutic target in the treatment of HCC.
Orbit Propagation and Determination of Low Earth Orbit Satellites
Directory of Open Access Journals (Sweden)
Ho-Nien Shou
2014-01-01
Full Text Available This paper represents orbit propagation and determination of low Earth orbit (LEO satellites. Satellite global positioning system (GPS configured receiver provides position and velocity measures by navigating filter to get the coordinates of the orbit propagation (OP. The main contradictions in real-time orbit which is determined by the problem are orbit positioning accuracy and the amount of calculating two indicators. This paper is dedicated to solving the problem of tradeoffs. To plan to use a nonlinear filtering method for immediate orbit tasks requires more precise satellite orbit state parameters in a short time. Although the traditional extended Kalman filter (EKF method is widely used, its linear approximation of the drawbacks in dealing with nonlinear problems was especially evident, without compromising Kalman filter (unscented Kalman Filter, UKF. As a new nonlinear estimation method, it is measured at the estimated measurements on more and more applications. This paper will be the first study on UKF microsatellites in LEO orbit in real time, trying to explore the real-time precision orbit determination techniques. Through the preliminary simulation results, they show that, based on orbit mission requirements and conditions using UKF, they can satisfy the positioning accuracy and compute two indicators.
Parallelism in matrix computations
Gallopoulos, Efstratios; Sameh, Ahmed H
2016-01-01
This book is primarily intended as a research monograph that could also be used in graduate courses for the design of parallel algorithms in matrix computations. It assumes general but not extensive knowledge of numerical linear algebra, parallel architectures, and parallel programming paradigms. The book consists of four parts: (I) Basics; (II) Dense and Special Matrix Computations; (III) Sparse Matrix Computations; and (IV) Matrix functions and characteristics. Part I deals with parallel programming paradigms and fundamental kernels, including reordering schemes for sparse matrices. Part II is devoted to dense matrix computations such as parallel algorithms for solving linear systems, linear least squares, the symmetric algebraic eigenvalue problem, and the singular-value decomposition. It also deals with the development of parallel algorithms for special linear systems such as banded ,Vandermonde ,Toeplitz ,and block Toeplitz systems. Part III addresses sparse matrix computations: (a) the development of pa...
International Nuclear Information System (INIS)
Strobel, E.L.
1985-01-01
Given the many conflicting experimental results, examination is made of the neutrino mass matrix in order to determine possible masses and mixings. It is assumed that the Dirac mass matrix for the electron, muon, and tau neutrinos is similar in form to those of the quarks and charged leptons, and that the smallness of the observed neutrino masses results from the Gell-Mann-Ramond-Slansky mechanism. Analysis of masses and mixings for the neutrinos is performed using general structures for the Majorana mass matrix. It is shown that if certain tentative experimental results concerning the neutrino masses and mixing angles are confirmed, significant limitations may be placed on the Majorana mass matrix. The most satisfactory simple assumption concerning the Majorana mass matrix is that it is approximately proportional to the Dirac mass matrix. A very recent experimental neutrino mass result and its implications are discussed. Some general properties of matrices with structure similar to the Dirac mass matrices are discussed
International Nuclear Information System (INIS)
Perdicakis, Michel
2012-01-01
Document available in extended abstract form only. In many countries, it is planned that the long life highly radioactive nuclear spent fuel will be stored in deep argillaceous rocks. The sites selected for this purpose are anoxic and satisfy several recommendations as mechanical stability, low permeability and low redox potential. Pyrite (FeS 2 ), iron(II) carbonate, iron(II) bearing clays and organic matter that are present in very small amounts (about 1% w:w) in soils play a major role in their reactivity and are considered today as responsible for the low redox potential values of these sites. In this communication, we describe an electrochemical technique derived from 'Salt matrix voltammetry' and allowing the almost in-situ voltammetric characterization of air-sensitive samples of soils after the only addition of the minimum humidity required for electrolytic conduction. Figure 1 shows the principle of the developed technique. It consists in the entrapment of the clay sample between a graphite working electrode and a silver counter/quasi-reference electrode. The sample was previously humidified by passing a water saturated inert gas through the electrochemical cell. The technique leads to well-defined voltammetric responses of the electro-active components of the clays. Figure 2 shows a typical voltammogram relative to a Callovo-Oxfordian argillite sample from Bure, the French place planned for the underground nuclear waste disposal. During the direct scan, one can clearly distinguish the anodic voltammetric signals for the oxidation of the iron (II) species associated with the clay and the oxidation of pyrite. The reverse scan displays a small cathodic signal for the reduction of iron (III) associated with the clay that demonstrates that the majority of the previously oxidized iron (II) species were transformed into iron (III) oxides reducible at lower potentials. When a second voltammetric cycle is performed, one can notice that the signal for iron (II
International Nuclear Information System (INIS)
Heggarty, J.W.
1999-06-01
response to the challenge of achieving parallel R-matrix computation. The primary objective was to develop parallel codes, targeted at multicomputers, that are capable of performing R-matrix calculations hitherto intractable using classic supercomputers. In particular, Fortran implementations of two internal region methods (the R-matrix Floquet method and the two-dimensional R-matrix propagation method) and three external region methods (the Light-Walker propagation method, the Baluja, Burke and Morgan propagation method and the Variable Phase Method) from four widely utilised R-matrix packages were investigated to ascertain whether, in these cases, parallel R-matrix computation was practicable and, if so, to determine the most effective way to port such codes to contemporary multicomputers. When attempting to develop the parallel codes, a number of computer aided automatic parallelization tools were investigated. These were found to be inadequate. Consequently, a parallelization approach was developed to provide simple guidelines for manual parallelization. This parallelization approach proved effective and efficient parallel versions of the five R-matrix codes were successfully developed. (author)
A Typical Presentation of Orbital Pseudotumor Mimicking Orbital Cellulitis
Directory of Open Access Journals (Sweden)
J. Ayatollahi
2013-10-01
Full Text Available Introduction: Orbital pseudotumor, also known as idiopathic orbital inflammatory syndrome (IOIS, is a benign, non- infective inflammatory condition of the orbit without identifiable local or systemic causes. The disease may mimics a variety of pathologic conditions. We pre-sent a case of pseudotumor observed in a patient admitted under the name of orbital celluli-ties. Case Report: A 26-year-old woman reffered to our hospital with the history of left ocular pain and headache 2 days before her visit.. Ophthalmological examination of the patient was normal except for the redness and lid edema, mild chemosis and conjunctival injection. Gen-eral assessment was normal but a low grade fever was observed. She was hospitalized as an orbital cellulitis patient. She was treated with intravenous antibiotics. On the third day , sud-denly diplopia, proptosis in her left eye and ocular pain in her right side appeared. MRI re-vealed bilateral enlargement of extraocular muscles. Diagnosis of orbital pseudotumor was made and the patient was treated with oral steroid.She responded promptly to the treatment. Antibiotics were discontinued and steroid was tapered in one month period under close fol-low up. Conclusion: The clinical features of orbital pseudotumor vary widely . Orbital pseudotumor and orbital cellulitis can occasionally demonstrate overlapping features.. Despite complete physical examination and appropriate imaging, sometimes correct diagnosis of the disease would be difficult (Sci J Hamadan Univ Med Sci 2013; 20 (3:256-259
Directory of Open Access Journals (Sweden)
Cudic Mare
2007-10-01
Full Text Available Abstract Background The M2 ectodomain (M2e of influenza A virus (IAV strains that have circulated in humans during the past 90 years shows remarkably little structural diversity. Since M2e-specific antibodies (Abs are capable of restricting IAV replication in vivo but are present only at minimal concentration in human sera, efforts are being made to develop a M2e-specific vaccine. We are exploring a synthetic multiple antigenic peptide (MAP vaccine and here report on the role of adjuvants (cholera toxin and immunostimulatory oligodeoxynucleotide and route of immunization on Ab response and strength of protection. Results Independent of adjuvants and immunization route, on average 87% of the M2e-MAP-induced Abs were specific for M2e peptide and a variable fraction of these M2e(pep-specific Abs (average 15% cross-reacted with presumably native M2e expressed by M2-transfected cells. The titer of these cross-reactive M2e(pep-nat-specific Abs in sera of parenterally immunized mice displayed a sigmoidal relation to level of protection, with EC50 of ~20 μg Ab/ml serum, though experiments with passive M2e(pep-nat Abs indicated that serum Abs did not fully account for protection in parenterally vaccinated mice, particularly in upper airways. Intranasal vaccination engendered stronger protection and a higher proportion of G2a Abs than parenteral vaccination, and the strength of protection failed to correlate with M2e(pep-nat-specific serum Ab titers, suggesting a role of airway-associated immunity in protection of intranasally vaccinated mice. Intranasal administration of M2e-MAP without adjuvant engendered no response but coadministration with infectious IAV slightly enhanced the M2e(pep-nat Ab response and protection compared to vaccination with IAV or adjuvanted M2e-MAP alone. Conclusion M2e-MAP is an effective immunogen as ~15% of the total M2e-MAP-induced Ab response is of desired specificity. While M2e(pep-nat-specific serum Abs have an important
Orbital preservation in a maxillectomy
Energy Technology Data Exchange (ETDEWEB)
Tanaka, Katsuhiko; Nishikawa, Hitomi; Kumagai, Masahiko; Dosaka, Yoshihiro; Kuroda, Toru; Atago, Yoshihiro; Nishio, Masamichi [Sapporo National Hospital (Japan)
1999-07-01
In the past 9 years, 38 patients of the maxillary cancer were treated by a combination of radiation and surgery. Sixteen patients showed the orbital involvement as confirmed by a CT scan and/or MRI. An orbital excenteration was necessary in 6 patients, due mainly to deep intraorbital invasion, while in 10, the orbital contents were preserved despite the involvement of the orbital capsule. The local rate of the orbital region in the latter patients evaluated at 48 months after the initial surgery was 44%. For the treatment of the recurrence at the orbital capsule. The application of gold grain (Au{sup 198}) thus appeared to be a useful tool for further preserving the eye. (author)
Orbital preservation in a maxillectomy
International Nuclear Information System (INIS)
Tanaka, Katsuhiko; Nishikawa, Hitomi; Kumagai, Masahiko; Dosaka, Yoshihiro; Kuroda, Toru; Atago, Yoshihiro; Nishio, Masamichi
1999-01-01
In the past 9 years, 38 patients of the maxillary cancer were treated by a combination of radiation and surgery. Sixteen patients showed the orbital involvement as confirmed by a CT scan and/or MRI. An orbital excenteration was necessary in 6 patients, due mainly to deep intraorbital invasion, while in 10, the orbital contents were preserved despite the involvement of the orbital capsule. The local rate of the orbital region in the latter patients evaluated at 48 months after the initial surgery was 44%. For the treatment of the recurrence at the orbital capsule. The application of gold grain (Au 198 ) thus appeared to be a useful tool for further preserving the eye. (author)
On the observability of the quark orbital angular momentum distribution
Energy Technology Data Exchange (ETDEWEB)
Courtoy, Aurore, E-mail: aurore.courtoy@ulg.be [IFPA, AGO Department, Université de Liège, Bât. B5, Sart Tilman, B-4000 Liège (Belgium); Laboratori Nazionali di Frascati, INFN, Frascati (Italy); Goldstein, Gary R., E-mail: gary.goldstein@tufts.edu [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Osvaldo Gonzalez Hernandez, J., E-mail: jog4m@virginia.edu [Istituto Nazionale di Fisica Nucleare (INFN) – Sezione di Torino, via P. Giuria, 1, 10125 Torino (Italy); Liuti, Simonetta, E-mail: sl4y@virginia.edu [University of Virginia – Physics Department, 382 McCormick Rd., Charlottesville, VA 22904 (United States); Laboratori Nazionali di Frascati, INFN, Frascati (Italy); Rajan, Abha, E-mail: ar5xc@virginia.edu [University of Virginia – Physics Department, 382 McCormick Rd., Charlottesville, VA 22904 (United States)
2014-04-04
We argue that due to parity constraints, the helicity combination of the purely momentum space counterparts of the Wigner distributions – the generalized transverse momentum distributions – that describes the configuration of an unpolarized quark in a longitudinally polarized nucleon can enter the deeply virtual Compton scattering amplitude only through matrix elements involving a final state interaction. The relevant matrix elements in turn involve light-cone operators projections in the transverse direction, or they appear in the deeply virtual Compton scattering amplitude at twist three. Orbital angular momentum or the spin structure of the nucleon was a major reason for these various distributions and amplitudes to have been introduced. We show that the twist three contributions associated with orbital angular momentum are related to the target-spin asymmetry in deeply virtual Compton scattering, already measured at HERMES.
International Nuclear Information System (INIS)
Michelotti, L.
1989-03-01
Unlike the other documents in these proceedings, this paper is neither a scientific nor a technical report. It is, rather, a short personal essay which attempts to describe an Exploratory Orbit Analysis (EOA) environment. Analyzing the behavior of a four or six dimensional nonlinear dynamical system is at least as difficult as analyzing events in high-energy collisions; the consequences of doing it badly, or slowly, would be at least as devastating; and yet the level of effort and expenditure invested in the latter, the very attention paid to it by physicists at large, must be two orders of magnitude greater than that given to the former. It is difficult to choose the model which best explains the behavior of a physical device if one does not first understand the behavior of the available models. The time is ripe for the development of a functioning EOA environment, which I will try to describe in this paper to help us achieve this goal
International Nuclear Information System (INIS)
Foster, Dean P; Langford, John; Perez-Giz, Gabe
2016-01-01
We study a spherically symmetric solution to the Einstein equations in which the source, which we call an orbiting radiation star (OR-star), is a compact object consisting of freely falling null particles. The solution avoids quantum scale regimes and hence neither relies upon nor ignores the interaction of quantum mechanics and gravitation. The OR-star spacetime exhibits a deep gravitational well yet remains singularity free. In fact, it is geometrically flat in the vicinity of the origin, with the flat region being of any desirable scale. The solution is observationally distinct from a black hole because a photon from infinity aimed at an OR-star escapes to infinity with a time delay. (paper)
Energy Technology Data Exchange (ETDEWEB)
Michelotti, L.
1989-03-01
Unlike the other documents in these proceedings, this paper is neither a scientific nor a technical report. It is, rather, a short personal essay which attempts to describe an Exploratory Orbit Analysis (EOA) environment. Analyzing the behavior of a four or six dimensional nonlinear dynamical system is at least as difficult as analyzing events in high-energy collisions; the consequences of doing it badly, or slowly, would be at least as devastating; and yet the level of effort and expenditure invested in the latter, the very attention paid to it by physicists at large, must be two orders of magnitude greater than that given to the former. It is difficult to choose the model which best explains the behavior of a physical device if one does not first understand the behavior of the available models. The time is ripe for the development of a functioning EOA environment, which I will try to describe in this paper to help us achieve this goal.
Directory of Open Access Journals (Sweden)
Deniz Marangoz
2016-10-01
Full Text Available A 29-year-old female patient presented with a painless mass on her upper eyelid medially. She noticed the mass 4 years earlier and it had increased in size over time. She had no diplopia, eyelid swelling, skin lesion overlying the mass, or visual disturbances. On ocular examination, eye movements and funduscopy were normal. The mass was movable and painless with palpation. Magnetic resonance imaging with contrast showed a 12x8x7 mm well-circumscribed cystic lesion with no contrast dye appearance. Surgical removal was performed delicately and no capsular rupture occured. Pathological examination revealed an eccrine hidrocystoma. Our aim is to underline that eccrine hidrocystoma should be included in differential diagnosis of orbital masses.
Cioslowski, Jerzy
2018-04-01
The dependence of the natural amplitudes of the harmonium atom in its ground state on the confinement strength ω is thoroughly investigated. A combination of rigorous analysis and extensive, highly accurate numerical calculations reveals the presence of only one positive-valued natural amplitude ("the normal sign pattern") for all ω ≥1/2 . More importantly, it is shown that unusual, weakly occupied natural orbitals (NOs) corresponding to additional positive-valued natural amplitudes emerge upon sufficient weakening of the confinement. These solitonic NOs, whose shapes remain almost invariant as their radial positions drift toward infinity upon the critical values of ω being approached from below, exhibit strong radial localization. Their asymptotic properties are extracted from the numerical data and their relevance to calculations on fully Coulombic systems is discussed.
Stability regions for synchronized τ-periodic orbits of coupled maps with coupling delay τ
Energy Technology Data Exchange (ETDEWEB)
Karabacak, Özkan, E-mail: ozkan2917@gmail.com [Department of Electronics and Communication Engineering, Istanbul Technical University, 34469 Istanbul (Turkey); Department of Electronic Systems, Aalborg University, 9220 Aalborg East (Denmark); Alikoç, Baran, E-mail: alikoc@itu.edu.tr [Department of Control and Automation Engineering, Istanbul Technical University, 34469 Istanbul (Turkey); Atay, Fatihcan M., E-mail: atay@member.ams.org [Department of Mathematics, Bilkent University, 06800 Ankara (Turkey)
2016-09-15
Motivated by the chaos suppression methods based on stabilizing an unstable periodic orbit, we study the stability of synchronized periodic orbits of coupled map systems when the period of the orbit is the same as the delay in the information transmission between coupled units. We show that the stability region of a synchronized periodic orbit is determined by the Floquet multiplier of the periodic orbit for the uncoupled map, the coupling constant, the smallest and the largest Laplacian eigenvalue of the adjacency matrix. We prove that the stabilization of an unstable τ-periodic orbit via coupling with delay τ is possible only when the Floquet multiplier of the orbit is negative and the connection structure is not bipartite. For a given coupling structure, it is possible to find the values of the coupling strength that stabilizes unstable periodic orbits. The most suitable connection topology for stabilization is found to be the all-to-all coupling. On the other hand, a negative coupling constant may lead to destabilization of τ-periodic orbits that are stable for the uncoupled map. We provide examples of coupled logistic maps demonstrating the stabilization and destabilization of synchronized τ-periodic orbits as well as chaos suppression via stabilization of a synchronized τ-periodic orbit.
DEFF Research Database (Denmark)
Mackey, Abigail; Brandstetter, Simon; Schjerling, Peter
2011-01-01
) 30 d later, or 30 d after a single stimulation bout (RBc). A muscle biopsy was collected from the control leg for comparison with the stimulated leg. Satellite cell content, tenascin C, and muscle regeneration were assessed by immunohistochemistry; real-time PCR was used to measure mRNA levels...... of collagens, laminins, heat-shock proteins (HSPs), inflammation, and related growth factors. The large responses of HSPs, CCL2, and tenascin C detected 48 h after a single bout were attenuated in the RB trial, indicative of protection against injury. Satellite cell content and 12 target genes, including IGF-1......, were elevated 30 d after a single bout. Among those displaying the greatest difference vs. control muscle, ECM laminin-ß1 and collagen types I and III were elevated ~6- to 9-fold (P...
International Nuclear Information System (INIS)
West, Aaron C.; Schmidt, Michael W.; Gordon, Mark S.; Ruedenberg, Klaus
2013-01-01
Through a basis-set-independent web of localizing orbital-transformations, the electronic wave function of a molecule is expressed in terms of a set of orbitals that reveal the atomic structure and the bonding pattern of a molecule. The analysis is based on resolving the valence orbital space in terms of an internal space, which has minimal basis set dimensions, and an external space. In the internal space, oriented quasi-atomic orbitals and split-localized molecular orbitals are determined by new, fast localization methods. The density matrix between the oriented quasi-atomic orbitals as well as the locations of the split-localized orbitals exhibit atomic populations and inter-atomic bonding patterns. A correlation-adapted quasi-atomic basis is determined in the external orbital space. The general formulations are specified in detail for Hartree-Fock wave functions. Applications to specific molecules exemplify the general scheme
International Nuclear Information System (INIS)
Trippe, S; Gillessen, S; Ott, T; Eisenhauer, F; Paumard, T; Martins, F; Genzel, R; Schoedel, R; Eckart, A; Alexander, T
2006-01-01
In this article we present and discuss the latest results from the observations of stars (''S-stars'') orbiting Sgr A* . With improving data quality the number of observed S-stars has increased substantially in the last years. The combination of radial velocity and proper motion information allows an ever more precise determination of orbital parameters and of the mass of and the distance to the supermassive black hole in the centre of the Milky Way. Additionally, the orbital solutions allow us to verify an agreement between the NIR source Sgr A* and the dynamical centre of the stellar orbits to within 2 mas
Accelerated testing for synchronous orbits
Mcdermott, P.
1981-01-01
Degradation of batteries during synchronous orbits is analyzed. Discharge and recharge rates are evaluated. The functional relationship between charge rate and degradation is mathematically determined.
The conservation of orbital symmetry
Woodward, R B
2013-01-01
The Conservation of Orbital Symmetry examines the principle of conservation of orbital symmetry and its use. The central content of the principle was that reactions occur readily when there is congruence between orbital symmetry characteristics of reactants and products, and only with difficulty when that congruence does not obtain-or to put it more succinctly, orbital symmetry is conserved in concerted reaction. This principle is expected to endure, whatever the language in which it may be couched, or whatever greater precision may be developed in its application and extension. The book ope
DEFF Research Database (Denmark)
Hansen, Kristoffer Arnsfelt; Ibsen-Jensen, Rasmus; Podolskii, Vladimir V.
2013-01-01
For matrix games we study how small nonzero probability must be used in optimal strategies. We show that for image win–lose–draw games (i.e. image matrix games) nonzero probabilities smaller than image are never needed. We also construct an explicit image win–lose game such that the unique optimal...
DEFF Research Database (Denmark)
Schneider, Jesper Wiborg; Borlund, Pia
2007-01-01
The present two-part article introduces matrix comparison as a formal means for evaluation purposes in informetric studies such as cocitation analysis. In the first part, the motivation behind introducing matrix comparison to informetric studies, as well as two important issues influencing such c...
Saleem, M
2002-01-01
The Unitarity of the CKM matrix is examined in the light of the latest available accurate data. The analysis shows that a conclusive result cannot be derived at present. Only more precise data can determine whether the CKM matrix opens new vistas beyond the standard model or not.
International Nuclear Information System (INIS)
Markowski, Adam S.; Mannan, M. Sam
2008-01-01
A risk matrix is a mechanism to characterize and rank process risks that are typically identified through one or more multifunctional reviews (e.g., process hazard analysis, audits, or incident investigation). This paper describes a procedure for developing a fuzzy risk matrix that may be used for emerging fuzzy logic applications in different safety analyses (e.g., LOPA). The fuzzification of frequency and severity of the consequences of the incident scenario are described which are basic inputs for fuzzy risk matrix. Subsequently using different design of risk matrix, fuzzy rules are established enabling the development of fuzzy risk matrices. Three types of fuzzy risk matrix have been developed (low-cost, standard, and high-cost), and using a distillation column case study, the effect of the design on final defuzzified risk index is demonstrated
International Nuclear Information System (INIS)
Baron, Jorge H.; Rivera, S.S.
2000-01-01
The so-called vulnerability matrix is used in the evaluation part of the probabilistic safety assessment for a nuclear power plant, during the containment event trees calculations. This matrix is established from what is knows as Numerical Categories for Engineering Judgement. This matrix is usually established with numerical values obtained with traditional arithmetic using the set theory. The representation of this matrix with fuzzy numbers is much more adequate, due to the fact that the Numerical Categories for Engineering Judgement are better represented with linguistic variables, such as 'highly probable', 'probable', 'impossible', etc. In the present paper a methodology to obtain a Fuzzy Vulnerability Matrix is presented, starting from the recommendations on the Numerical Categories for Engineering Judgement. (author)
Spin-inversion in nanoscale graphene sheets with a Rashba spin-orbit barrier
Directory of Open Access Journals (Sweden)
Somaieh Ahmadi
2012-03-01
Full Text Available Spin-inversion properties of an electron in nanoscale graphene sheets with a Rashba spin-orbit barrier is studied using transfer matrix method. It is found that for proper values of Rashba spin-orbit strength, perfect spin-inversion can occur in a wide range of electron incident angle near the normal incident. In this case, the graphene sheet with Rashba spin-orbit barrier can be considered as an electron spin-inverter. The efficiency of spin-inverter can increase up to a very high value by increasing the length of Rashba spin-orbit barrier. The effect of intrinsic spin-orbit interaction on electron spin inversion is then studied. It is shown that the efficiency of spin-inverter decreases slightly in the presence of intrinsic spin-orbit interaction. The present study can be used to design graphene-based spintronic devices.
The classical r-matrix method for nonlinear sigma-model
Sevostyanov, Alexey
1995-01-01
The canonical Poisson structure of nonlinear sigma-model is presented as a Lie-Poisson r-matrix bracket on coadjoint orbits. It is shown that the Poisson structure of this model is determined by some `hidden singularities' of the Lax matrix.
A matrix model from string field theory
Directory of Open Access Journals (Sweden)
Syoji Zeze
2016-09-01
Full Text Available We demonstrate that a Hermitian matrix model can be derived from level truncated open string field theory with Chan-Paton factors. The Hermitian matrix is coupled with a scalar and U(N vectors which are responsible for the D-brane at the tachyon vacuum. Effective potential for the scalar is evaluated both for finite and large N. Increase of potential height is observed in both cases. The large $N$ matrix integral is identified with a system of N ZZ branes and a ghost FZZT brane.
Zuo, Xiangyang; Pan, Wen; Feng, Tingting; Shi, Xiaohong; Dai, Jianfeng
2014-01-01
Dengue virus (DENV), the causative agent of human Dengue hemorrhagic fever, is a mosquito-borne virus of immense global health importance. Characterization of cellular factors promoting or inhibiting DENV infection is important for understanding the mechanism of DENV infection. In this report, MMP3 (stromelysin-1), a secretory endopeptidase that degrades extracellular matrices, has been shown promoting cellular antiviral response against DENV infection. Quantitative RT-PCR and Western Blot showed that the expression of MMP3 was upregulated in DENV-infected RAW264.7 cells. The intracellular viral loads were significantly higher in MMP3 silenced cells compared with controls. The expression level of selective anti-viral cytokines were decreased in MMP3 siRNA treated cells, and the transcription factor activity of NFκB was significantly impaired upon MMP3 silencing during DENV infection. Further, we found that MMP3 moved to cell nucleus upon DENV infection and colocalized with NFκB P65 in nucleus. Co-immunoprecipitation analysis suggested that MMP3 directly interacted with NFκB in nucleus during DENV infection and the C-terminal hemopexin-like domain of MMP3 was required for the interaction. This study suggested a novel role of MMP3 in nucleus during viral infection and provided new evidence for MMPs in immunomodulation.
PyORBIT: A Python Shell For ORBIT
Energy Technology Data Exchange (ETDEWEB)
Jean-Francois Ostiguy; Jeffrey Holmes
2003-07-01
ORBIT is code developed at SNS to simulate beam dynamics in accumulation rings and synchrotrons. The code is structured as a collection of external C++ modules for SuperCode, a high level interpreter shell developed at LLNL in the early 1990s. SuperCode is no longer actively supported and there has for some time been interest in replacing it by a modern scripting language, while preserving the feel of the original ORBIT program. In this paper, we describe a new version of ORBIT where the role of SuperCode is assumed by Python, a free, well-documented and widely supported object-oriented scripting language. We also compare PyORBIT to ORBIT from the standpoint of features, performance and future expandability.
Orbital Chondroma: A rare mesenchymal tumor of orbit
Directory of Open Access Journals (Sweden)
Ruchi S Kabra
2015-01-01
Full Text Available While relatively common in the skeletal system, cartilaginous tumors are rarely seen originating from the orbit. Here, we report a rare case of an orbital chondroma. A 27-year-old male patient presented with a painless hard mass in the superonasal quadrant (SNQ of left orbit since 3 months. On examination, best-corrected visual acuity of both eyes was 20/20, with normal anterior and posterior segment with full movements of eyeballs and normal intraocular pressure. Computerized tomography scan revealed well defined soft tissue density lesion in SNQ of left orbit. Patient was operated for anteromedial orbitotomy under general anesthesia. Mass was excised intact and sent for histopathological examination (HPE. HPE report showed lobular aggregates of benign cartilaginous cells with mild atypia suggesting of benign cartilaginous tumor - chondroma. Very few cases of orbital chondroma have been reported in literature so far.
PyORBIT: A Python Shell For ORBIT
International Nuclear Information System (INIS)
Jean-Francois Ostiguy; Jeffrey Holmes
2003-01-01
ORBIT is code developed at SNS to simulate beam dynamics in accumulation rings and synchrotrons. The code is structured as a collection of external C++ modules for SuperCode, a high level interpreter shell developed at LLNL in the early 1990s. SuperCode is no longer actively supported and there has for some time been interest in replacing it by a modern scripting language, while preserving the feel of the original ORBIT program. In this paper, we describe a new version of ORBIT where the role of SuperCode is assumed by Python, a free, well-documented and widely supported object-oriented scripting language. We also compare PyORBIT to ORBIT from the standpoint of features, performance and future expandability
International Nuclear Information System (INIS)
Handler, L.C.; Davey, I.C.; Hill, J.C.; Lauryssen, C.
1991-01-01
A series of 65 patients suffering from acute inflammatory disease of the orbit was studied by CT. Ethmoiditis was the cause in the vast majority; trauma and dental extraction played a lesser role in causation. Orbital cellulitis was diagnosed in 17 and subperiosteal abscess in the remaining 48. It was not possible to differentiate 33 pus-containing abscesses from the six with inflammatory masses (phlegmons). The satisfactory response to aggressive medical treatment in those patients with inflammatory masses that were not drained justifies a more conservative approach; surgical drainage being reserved for those with a deterioration in proptosis, ocular movements or vision. Six abscesses arose de novo, of which some were in the orbital fat rather than the subperiosteal space. (orig.)
Supervoltage orbital radiotherapy for progressive Graves' ophthalmopathy
International Nuclear Information System (INIS)
Kriss, J.P.; McDougall, I.R.; Petersen, I.A.; Donaldson, S.S.
1989-01-01
Since 1968 we have employed supervoltage orbital radiation as treatment for severe progressive Graves' ophthalmopathy. A numerical ophthalmic index was used to asess pre- and post-treatment serverity. In the past 20 years we have treated 311 patients of whom 275 have been followed for ≤ 1 year or until any eye surgery was performed. An orbital radiation dosage of 2000 rads in 2 weeks was used for the majority of patients (Series I and III). Series II patients received an orbital dose of 3000 rads in 3 weeks. Demographic differences were observed between these series, thus mandating presentation of the results of each separately. Analyses excluded any result achieved by any post-radiation surgical procedure on the eyes. Post-theraphy worsening of ophtalmopathy occurred in only 29 of 1025 observations. Improvement or complete resolution was observed within each category of eye involvement, but lack of favorable response was also recorded in significant numbers. Improvement in proptosis occurred with the lowest frequency and magnitude. About 30% of the patients required eye muscle surgery to correct residual diplopia. Analysis of the data by step-wise linear regression analysis enabled us a. to derive formulae predicting the problable response to radiation therapy according to sign and severity, and b. identify parameters which diminished the likelihood or the extent of a favorable response. The latter included male sex, never thyrotoxic, age greater than 60 years, and requirement for concomitant treatment for hyperthyroidism. No long-term adverse reactions attributable to the radiotherapy have been observed. We conclude that supervoltage orbital radiotherapy, combined with later eye muscle surgery if necessary, is an effective treatment strategy for progressive Graves' ophthalmopathy. (author)
Spin-orbital quantum liquid on the honeycomb lattice
Corboz, Philippe
2013-03-01
The symmetric Kugel-Khomskii can be seen as a minimal model describing the interactions between spin and orbital degrees of freedom in transition-metal oxides with orbital degeneracy, and it is equivalent to the SU(4) Heisenberg model of four-color fermionic atoms. We present simulation results for this model on various two-dimensional lattices obtained with infinite projected-entangled pair states (iPEPS), an efficient variational tensor-network ansatz for two dimensional wave functions in the thermodynamic limit. This approach can be seen as a two-dimensional generalization of matrix product states - the underlying ansatz of the density matrix renormalization group method. We find a rich variety of exotic phases: while on the square and checkerboard lattices the ground state exhibits dimer-Néel order and plaquette order, respectively, quantum fluctuations on the honeycomb lattice destroy any order, giving rise to a spin-orbital liquid. Our results are supported from flavor-wave theory and exact diagonalization. Furthermore, the properties of the spin-orbital liquid state on the honeycomb lattice are accurately accounted for by a projected variational wave-function based on the pi-flux state of fermions on the honeycomb lattice at 1/4-filling. In that state, correlations are algebraic because of the presence of a Dirac point at the Fermi level, suggesting that the ground state is an algebraic spin-orbital liquid. This model provides a good starting point to understand the recently discovered spin-orbital liquid behavior of Ba3CuSb2O9. The present results also suggest to choose optical lattices with honeycomb geometry in the search for quantum liquids in ultra-cold four-color fermionic atoms. We acknowledge the financial support from the Swiss National Science Foundation.
Energy Technology Data Exchange (ETDEWEB)
Leal A, B.; Mireles G, F.; Quirino T, L.; Pinedo, J.L. [Universidad Autonoma de Zacatecas, Zacatecas (Mexico)]. e-mail: bleal79@yahoo.com.mx
2005-07-01
In the area of the Radiological Safety it is required of a calibrated detection system in energy and efficiency for the determination of the concentration in activity in samples that vary in chemical composition and by this in density. The area of Nuclear Engineering requires to find the grade of isotopic enrichment of the uranium of the Sub-critic Nuclear Chicago 9000 Mark. Given the experimental importance that has the determination from the curves of efficiency to the effects of establishing the quantitative results, is appealed to the simulation of the response function of the detector used in the Regional Center of Nuclear Studies inside the range of energy of 80 keV to 1400 keV varying the density of the matrix and the chemical composition by means of the application of the Monte Carlo code MCNP-4A. The obtained results in the simulation of the response function of the detector show a grade of acceptance in the range from 500 to 1400 keV energy, with a smaller percentage discrepancy to 10%, in the range of low energy that its go from 59 to 400 keV, the percentage discrepancy varies from 17% until 30%, which is manifested in the opposing isotopic relationship for 5 fuel rods of the Sub critic nuclear assemble. (Author)
A case report of orbital Langerhans cell histiocytosis presenting as a orbital cellulitis.
Albert-Fort, M; González-Candial, M
2018-04-08
A 10-year-old girl was seen with a 3-week history of right upper lid swelling and with no other symptoms or fever. There was no recent history of sinusitis, trauma, or previous infection involving the periorbital area, or response to oral antibiotic treatment. Orbital computed tomography showed a lesion involving the upper margin of the orbit, and bone destruction at the orbital roof. Biopsy performed revealed the presence of Langerhans cell Histiocytosis. The lesion was surgically debulked and corticosteroids were used intra-operatively. The lesion responded to treatment. The orbital involvement of Langerhans cell histiocytosis, despite its low incidence, should be considered in the examination of acute peri-orbital swelling. It usually presents as an osteolytic lesion, and it is confirmed with a histological examination and immunohistochemical techniques for CD1a and S100. An interdisciplinary approach is recommended to rule out multifocal or multisystemic diseases, as well as to develop an appropriate treatment strategy. Copyright © 2018 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.
International Nuclear Information System (INIS)
Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.; and Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794)
1976-01-01
Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the Aapprox. =18 region are performed following this procedure and treating the Pauli exclusion operator Q 2 /sub p/ by the method of Tsai and Kuo. The treatment of Q 2 /sub p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close agreement is obtained with the matrix elements calculated by Kuo and Brown using approximate methods
Infected orbital cyst following exenteration.
Barak, A; Hirsh, A; Rosner, M; Rosen, N
1996-09-01
An orbital cyst is a rare complication of orbital trauma and exenteration. Infections of such cysts have not been described, and are potentially dangerous unless treated immediately. The authors describe a case of delayed treatment of such an infected cyst, which resolved following surgical drainage. The potentially hazardous outcome makes knowledge of such cases important.
DEFF Research Database (Denmark)
Ramos, Juan David Hincapie; Tabard, Aurélien; Bardram, Jakob
2010-01-01
We introduce GridOrbit, a public awareness display that visualizes the activity of a community grid used in a biology laboratory. This community grid executes bioin-formatics algorithms and relies on users to donate CPU cycles to the grid. The goal of GridOrbit is to create a shared awareness about...
Diplopia and Orbital Wall Fractures
Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.
2014-01-01
Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and
Diplopia and orbital wall fractures
Boffano, P.; Roccia, F.; Gallesio, C.; Karagozoglu, K.H.; Forouzanfar, T.
2014-01-01
Diplopia is a symptom that is frequently associated with orbital wall fractures. The aim of this article was to present the incidence and patterns of diplopia after orbital wall blow-out fractures in 2 European centers, Turin and Amsterdam, and to identify any correlation between this symptom and
Matrix Metalloproteinase Enzyme Family
Directory of Open Access Journals (Sweden)
Ozlem Goruroglu Ozturk
2013-04-01
Full Text Available Matrix metalloproteinases play an important role in many biological processes such as embriogenesis, tissue remodeling, wound healing, and angiogenesis, and in some pathological conditions such as atherosclerosis, arthritis and cancer. Currently, 24 genes have been identified in humans that encode different groups of matrix metalloproteinase enzymes. This review discuss the members of the matrix metalloproteinase family and their substrate specificity, structure, function and the regulation of their enzyme activity by tissue inhibitors. [Archives Medical Review Journal 2013; 22(2.000: 209-220
Matrix groups for undergraduates
Tapp, Kristopher
2005-01-01
Matrix groups touch an enormous spectrum of the mathematical arena. This textbook brings them into the undergraduate curriculum. It makes an excellent one-semester course for students familiar with linear and abstract algebra and prepares them for a graduate course on Lie groups. Matrix Groups for Undergraduates is concrete and example-driven, with geometric motivation and rigorous proofs. The story begins and ends with the rotations of a globe. In between, the author combines rigor and intuition to describe basic objects of Lie theory: Lie algebras, matrix exponentiation, Lie brackets, and maximal tori.
Eves, Howard
1980-01-01
The usefulness of matrix theory as a tool in disciplines ranging from quantum mechanics to psychometrics is widely recognized, and courses in matrix theory are increasingly a standard part of the undergraduate curriculum.This outstanding text offers an unusual introduction to matrix theory at the undergraduate level. Unlike most texts dealing with the topic, which tend to remain on an abstract level, Dr. Eves' book employs a concrete elementary approach, avoiding abstraction until the final chapter. This practical method renders the text especially accessible to students of physics, engineeri
A method of orbital analysis for large-scale first-principles simulations
International Nuclear Information System (INIS)
Ohwaki, Tsukuru; Otani, Minoru; Ozaki, Taisuke
2014-01-01
An efficient method of calculating the natural bond orbitals (NBOs) based on a truncation of the entire density matrix of a whole system is presented for large-scale density functional theory calculations. The method recovers an orbital picture for O(N) electronic structure methods which directly evaluate the density matrix without using Kohn-Sham orbitals, thus enabling quantitative analysis of chemical reactions in large-scale systems in the language of localized Lewis-type chemical bonds. With the density matrix calculated by either an exact diagonalization or O(N) method, the computational cost is O(1) for the calculation of NBOs associated with a local region where a chemical reaction takes place. As an illustration of the method, we demonstrate how an electronic structure in a local region of interest can be analyzed by NBOs in a large-scale first-principles molecular dynamics simulation for a liquid electrolyte bulk model (propylene carbonate + LiBF 4 )
Nam, Kwangwoo; Sakai, Yuuki; Funamoto, Seiichi; Kimura, Tsuyoshi; Kishida, Akio
2011-01-01
In this study, we aimed to replicate the function of native tissues that can be used in tissue engineering and regenerative medicine. The key to such replication is the preparation of an artificial collagen matrix that possesses a structure resembling that of the extracellular matrix. We, therefore, prepared a collagen matrix by fibrillogenesis in a NaCl/Na(2)HPO(4) aqueous solution using a dialysis cassette and investigated its biological behavior in vitro and in vivo. The in vitro cell adhesion and proliferation did not show any significant differences. The degradation rate in the living body could be controlled according to the preparation condition, where the collagen matrix with high water content (F-collagen matrix, >98%) showed fast degradation and collagen matrix with lower water content (T-collagen matrix, >80%) showed no degradation for 8 weeks. The degradation did not affect the inflammatory response at all and relatively faster wound healing response was observed. Comparing this result with that of collagen gel and decellularized cornea, it can be concluded that the structural factor is very important and no cell abnormal behavior would be observed for quaternary structured collagen matrix.
Czerwinski, Michael; Spence, Jason R
2017-01-05
Recently in Nature, Gjorevski et al. (2016) describe a fully defined synthetic hydrogel that mimics the extracellular matrix to support in vitro growth of intestinal stem cells and organoids. The hydrogel allows exquisite control over the chemical and physical in vitro niche and enables identification of regulatory properties of the matrix. Copyright © 2017 Elsevier Inc. All rights reserved.
The Matrix Organization Revisited
DEFF Research Database (Denmark)
Gattiker, Urs E.; Ulhøi, John Parm
1999-01-01
This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively).......This paper gives a short overview of matrix structure and technology management. It outlines some of the characteristics and also points out that many organizations may actualy be hybrids (i.e. mix several ways of organizing to allocate resorces effectively)....
Directory of Open Access Journals (Sweden)
Sumeet Jain
2016-01-01
Full Text Available Squamous cell carcinoma of the eyelid is the second most common malignant neoplasm of the eye with the incidence of 0.09 and 2.42 cases/100 000 people. Orbital invasion is a rare complication but, if recognized early, can be treated effectively with exenteration. Although with advancements in technology such as computer-aided design and computer-aided manufacturing, material science, and retentive methods like implants, orbital prosthesis with stock ocular prosthesis made of methyl methacrylate retained by anatomic undercuts is quiet effective and should not be overlooked and forgotten. This clinical report describes prosthetic rehabilitation of two male patients with polymethyl methacrylate resin orbital prosthesis after orbital exenteration, for squamous cell carcinoma of the upper eyelid. The orbital prosthesis was sufficiently retained by hard and soft tissue undercuts without any complications. The patients using the prosthesis are quite satisfied with the cosmetic results and felt comfortable attending the social events.
Koo, H.; Falsetta, M.L.; Klein, M.I.
2013-01-01
Many infectious diseases in humans are caused or exacerbated by biofilms. Dental caries is a prime example of a biofilm-dependent disease, resulting from interactions of microorganisms, host factors, and diet (sugars), which modulate the dynamic formation of biofilms on tooth surfaces. All biofilms have a microbial-derived extracellular matrix as an essential constituent. The exopolysaccharides formed through interactions between sucrose- (and starch-) and Streptococcus mutans-derived exoenzymes present in the pellicle and on microbial surfaces (including non-mutans) provide binding sites for cariogenic and other organisms. The polymers formed in situ enmesh the microorganisms while forming a matrix facilitating the assembly of three-dimensional (3D) multicellular structures that encompass a series of microenvironments and are firmly attached to teeth. The metabolic activity of microbes embedded in this exopolysaccharide-rich and diffusion-limiting matrix leads to acidification of the milieu and, eventually, acid-dissolution of enamel. Here, we discuss recent advances concerning spatio-temporal development of the exopolysaccharide matrix and its essential role in the pathogenesis of dental caries. We focus on how the matrix serves as a 3D scaffold for biofilm assembly while creating spatial heterogeneities and low-pH microenvironments/niches. Further understanding on how the matrix modulates microbial activity and virulence expression could lead to new approaches to control cariogenic biofilms. PMID:24045647
Orbital Evolution and Orbital Phase Resolved Spectroscopy of the ...
Indian Academy of Sciences (India)
binary. We have carried out orbital phase resolved spectroscopy to mea- ... agreement with a simple model of a spherically symmetric stellar wind from the .... has a set of Narrow Field Instruments (NFI) comprising one Low Energy Concen-.
Orbital Infarction due to Sickle Cell Disease without Orbital Pain
Directory of Open Access Journals (Sweden)
Cameron L. McBride
2016-01-01
Full Text Available Sickle cell disease is a hemoglobinopathy that results in paroxysmal arteriolar occlusion and tissue infarction that can manifest in a plurality of tissues. Rarely, these infarcted crises manifest in the bony orbit. Orbital infarction usually presents with acute onset of periorbital tenderness, swelling, erythema, and pain. Soft tissue swelling can result in proptosis and attenuation of extraocular movements. Expedient diagnosis of sickle cell orbital infarction is crucial because this is a potentially sight-threatening entity. Diagnosis can be delayed since the presentation has physical and radiographic findings mimicking various infectious and traumatic processes. We describe a patient who presented with sickle cell orbital crisis without pain. This case highlights the importance of maintaining a high index of suspicion in patients with known sickle cell disease or of African descent born outside the United States in a region where screening for hemoglobinopathy is not routine, even when the presentation is not classic.
Higgins, Chris
2012-01-01
This article presents the author's response to the reviews of his book, "The Good Life of Teaching: An Ethics of Professional Practice." He begins by highlighting some of the main concerns of his book. He then offers a brief response, doing his best to address the main criticisms of his argument and noting where the four reviewers (Charlene…
JSC Orbital Debris Website Description
Johnson, Nicholas L.
2006-01-01
Purpose: The website provides information about the NASA Orbital Debris Program Office at JSC, which is the lead NASA center for orbital debris research. It is recognized world-wide for its leadership in addressing orbital debris issues. The NASA Orbital Debris Program Office has taken the international lead in conducting measurements of the environment and in developing the technical consensus for adopting mitigation measures to protect users of the orbital environment. Work at the center continues with developing an improved understanding of the orbital debris environment and measures that can be taken to control its growth. Major Contents: Orbital Debris research is divided into the following five broad efforts. Each area of research contains specific information as follows: 1) Modeling - NASA scientists continue to develop and upgrade orbital debris models to describe and characterize the current and future debris environment. Evolutionary and engineering models are described in detail. Downloadable items include a document in PDF format and executable software. 2) Measurements - Measurements of near-Earth orbital debris are accomplished by conducting ground-based and space-based observations of the orbital debris environment. The data from these sources provide validation of the environment models and identify the presence of new sources. Radar, optical and surface examinations are described. External links to related topics are provided. 3) Protection - Orbital debris protection involves conducting hypervelocity impact measurements to assess the risk presented by orbital debris to operating spacecraft and developing new materials and new designs to provide better protection from the environment with less weight penalty. The data from this work provides the link between the environment defined by the models and the risk presented by that environment to operating spacecraft and provides recommendations on design and operations procedures to reduce the risk as
Thermal and mechanical behavior of metal matrix and ceramic matrix composites
Kennedy, John M. (Editor); Moeller, Helen H. (Editor); Johnson, W. S. (Editor)
1990-01-01
The present conference discusses local stresses in metal-matrix composites (MMCs) subjected to thermal and mechanical loads, the computational simulation of high-temperature MMCs' cyclic behavior, an analysis of a ceramic-matrix composite (CMC) flexure specimen, and a plasticity analysis of fibrous composite laminates under thermomechanical loads. Also discussed are a comparison of methods for determining the fiber-matrix interface frictional stresses of CMCs, the monotonic and cyclic behavior of an SiC/calcium aluminosilicate CMC, the mechanical and thermal properties of an SiC particle-reinforced Al alloy MMC, the temperature-dependent tensile and shear response of a graphite-reinforced 6061 Al-alloy MMC, the fiber/matrix interface bonding strength of MMCs, and fatigue crack growth in an Al2O3 short fiber-reinforced Al-2Mg matrix MMC.
Merriam, M. L.
2002-01-01
Traditional studies of Reusable Launch Vehicle (RLV) designs have focused on designs that are completely reusable except for the fuel. This may not be realistic with current technology . An alternate approach is to look at partially reusable launch vehicles. This raises the question of which parts should be reused and which parts should be expendable. One approach is to consider the cost/pound of returning these parts from orbit. With the shuttle, this cost is about three times the cost/pound of launching payload into orbit. A subtle corollary is that RLVs are much less practical for higher orbits, such as the one on which the International Space Station resides, than they are for low earth orbits.
NASA Orbital Debris Baseline Populations
Krisko, Paula H.; Vavrin, A. B.
2013-01-01
The NASA Orbital Debris Program Office has created high fidelity populations of the debris environment. The populations include objects of 1 cm and larger in Low Earth Orbit through Geosynchronous Transfer Orbit. They were designed for the purpose of assisting debris researchers and sensor developers in planning and testing. This environment is derived directly from the newest ORDEM model populations which include a background derived from LEGEND, as well as specific events such as the Chinese ASAT test, the Iridium 33/Cosmos 2251 accidental collision, the RORSAT sodium-potassium droplet releases, and other miscellaneous events. It is the most realistic ODPO debris population to date. In this paper we present the populations in chart form. We describe derivations of the background population and the specific populations added on. We validate our 1 cm and larger Low Earth Orbit population against SSN, Haystack, and HAX radar measurements.
Lidar Orbital Angular Momentum Sensor
National Aeronautics and Space Administration — The recognition in recent decades that electromagnetic fields have angular momentum (AM) in the form of not only polarization (or spin AM) but also orbital (OAM) has...
Real and Hybrid Atomic Orbitals.
Cook, D. B.; Fowler, P. W.
1981-01-01
Demonstrates that the Schrodinger equation for the hydrogenlike atom separates in both spheroconal and prolate spheroidal coordinates and that these separations provide a sound theoretical basis for the real and hybrid atomic orbitals. (Author/SK)
High Power Orbit Transfer Vehicle
National Research Council Canada - National Science Library
Gulczinski, Frank
2003-01-01
... from Virginia Tech University and Aerophysics, Inc. to examine propulsion requirements for a high-power orbit transfer vehicle using thin-film voltaic solar array technologies under development by the Space Vehicles Directorate (dubbed PowerSail...
Gradient-based stochastic estimation of the density matrix
Wang, Zhentao; Chern, Gia-Wei; Batista, Cristian D.; Barros, Kipton
2018-03-01
Fast estimation of the single-particle density matrix is key to many applications in quantum chemistry and condensed matter physics. The best numerical methods leverage the fact that the density matrix elements f(H)ij decay rapidly with distance rij between orbitals. This decay is usually exponential. However, for the special case of metals at zero temperature, algebraic decay of the density matrix appears and poses a significant numerical challenge. We introduce a gradient-based probing method to estimate all local density matrix elements at a computational cost that scales linearly with system size. For zero-temperature metals, the stochastic error scales like S-(d+2)/2d, where d is the dimension and S is a prefactor to the computational cost. The convergence becomes exponential if the system is at finite temperature or is insulating.
Economic analysis requirements in support of orbital debris regulatory policy
Greenberg, Joel S.
1996-10-01
As the number of Earth orbiting objects increases so does the potential for generating orbital debris with the consequent increase in the likelihood of impacting and damaging operating satellites. Various debris remediation approaches are being considered that encompass both in-orbit and return-to-Earth schema and have varying degrees of operations, cost, international competitiveness, and safety implications. Because of the diversity of issues, concerns and long-term impacts, there is a clear need for the setting of government policies that will lead to an orderly abatement of the potential orbital debris hazards. These policies may require the establishment of a supportive regulatory regime. The Department of Transportation is likely to have regulatory responsibilities relating to orbital debris stemming from its charge to protect the public health and safety, safety of property, and national security interests and foreign policy interests of the United States. This paper describes DOT's potential regulatory role relating to orbital debris remediation, the myriad of issues concerning the need for establishing government policies relating to orbital debris remediation and their regulatory implications, the proposed technological solutions and their economic and safety implications. Particular emphasis is placed upon addressing cost-effectiveness and economic analyses as they relate to economic impact analysis in support of regulatory impact analysis.
An Orbit And Dispersion Correction Scheme for the PEP II
International Nuclear Information System (INIS)
Cai, Y.; Donald, M.; Shoaee, H.; White, G.; Yasukawa, L.A.
2011-01-01
To achieve optimum luminosity in a storage ring it is vital to control the residual vertical dispersion. In the original PEP storage ring, a scheme to control the residual dispersion function was implemented using the ring orbit as the controlling element. The 'best' orbit not necessarily giving the lowest vertical dispersion. A similar scheme has been implemented in both the on-line control code and in the simulation code LEGO. The method involves finding the response matrices (sensitivity of orbit/dispersion at each Beam-Position-Monitor (BPM) to each orbit corrector) and solving in a least squares sense for minimum orbit, dispersion function or both. The optimum solution is usually a subset of the full least squares solution. A scheme of simultaneously correcting the orbits and dispersion has been implemented in the simulation code and on-line control system for PEP-II. The scheme is based on the eigenvector decomposition method. An important ingredient of the scheme is to choose the optimum eigenvectors that minimize the orbit, dispersion and corrector strength. Simulations indicate this to be a very effective way to control the vertical residual dispersion.
Bhatia, Rajendra
2013-01-01
This book is an outcome of the Indo-French Workshop on Matrix Information Geometries (MIG): Applications in Sensor and Cognitive Systems Engineering, which was held in Ecole Polytechnique and Thales Research and Technology Center, Palaiseau, France, in February 23-25, 2011. The workshop was generously funded by the Indo-French Centre for the Promotion of Advanced Research (IFCPAR). During the event, 22 renowned invited french or indian speakers gave lectures on their areas of expertise within the field of matrix analysis or processing. From these talks, a total of 17 original contribution or state-of-the-art chapters have been assembled in this volume. All articles were thoroughly peer-reviewed and improved, according to the suggestions of the international referees. The 17 contributions presented are organized in three parts: (1) State-of-the-art surveys & original matrix theory work, (2) Advanced matrix theory for radar processing, and (3) Matrix-based signal processing applications.
Topological imprint for periodic orbits
International Nuclear Information System (INIS)
Martín, Jesús San; Moscoso, Ma José; Gómez, A González
2012-01-01
The more self-crossing points an orbit has the more complex it is. We introduce the topological imprint to characterize crossing points and focus on the period-doubling cascade. The period-doubling cascade topological imprint determines the topological imprint for orbits in chaotic bands. In addition, there is a closer link between this concept and the braids studied by Lettelier et al (2000 J. Phys. A: Math. Gen. 33 1809–25). (paper)
Targeting Ballistic Lunar Capture Trajectories Using Periodic Orbits in the Sun-Earth CRTBP
Cooley, D.S.; Griesemer, Paul Ricord; Ocampo, Cesar
2009-01-01
A particular periodic orbit in the Earth-Sun circular restricted three body problem is shown to have the characteristics needed for a ballistic lunar capture transfer. An injection from a circular parking orbit into the periodic orbit serves as an initial guess for a targeting algorithm. By targeting appropriate parameters incrementally in increasingly complicated force models and using precise derivatives calculated from the state transition matrix, a reliable algorithm is produced. Ballistic lunar capture trajectories in restricted four body systems are shown to be able to be produced in a systematic way.
Spin-orbit torques in magnetic bilayers
Haney, Paul
2015-03-01
Spintronics aims to utilize the coupling between charge transport and magnetic dynamics to develop improved and novel memory and logic devices. Future progress in spintronics may be enabled by exploiting the spin-orbit coupling present at the interface between thin film ferromagnets and heavy metals. In these systems, applying an in-plane electrical current can induce magnetic dynamics in single domain ferromagnets, or can induce rapid motion of domain wall magnetic textures. There are multiple effects responsible for these dynamics. They include spin-orbit torques and a chiral exchange interaction (the Dzyaloshinskii-Moriya interaction) in the ferromagnet. Both effects arise from the combination of ferromagnetism and spin-orbit coupling present at the interface. There is additionally a torque from the spin current flux impinging on the ferromagnet, arising from the spin hall effect in the heavy metal. Using a combination of approaches, from drift-diffusion to Boltzmann transport to first principles methods, we explore the relative contributions to the dynamics from these different effects. We additionally propose that the transverse spin current is locally enhanced over its bulk value in the vicinity of an interface which is oriented normal to the charge current direction.
Thermoluminescence of meteorites and their orbits
Melcher, C. L.
1981-01-01
The thermoluminescence levels of 45 ordinary chondrites are measured in order to provide information on the orbital characteristics of the meteorites before impact. Glow curves of the photon emission response of powdered samples of the meteorites to temperatures up to 550 C in the natural state and following irradiation by a laboratory test dose of 110,000 rad were obtained as functions of terrestrial age and compared to those of samples of the Pribram, Lost City and Innisfree meteorites, for which accurate orbital data is available. The thermoluminescence levels in 40 out of 42 meteorites are found to be similar to those of the three control samples, indicating that the vast majority of ordinary chondrites that survive atmospheric entry have perihelia in the range 0.8-1 AU. Of the remaining two, Farmville is observed to exhibit an unusually large gradient in thermoluminescence levels with sample depth, which may be a result of a temperature gradient arising in a slowly rotating meteorite. Finally, the thermoluminescence measured in the Malakal meteorite is found to be two orders of magnitude lower than control samples, which is best explained by thermal draining by solar heating in an orbit with a perihelion distance of 0.5 to 0.6 AU.
Praeger, Cheryl; Tao, Terence
2018-01-01
MATRIX is Australia’s international, residential mathematical research institute. It facilitates new collaborations and mathematical advances through intensive residential research programs, each lasting 1-4 weeks. This book is a scientific record of the five programs held at MATRIX in its first year, 2016: Higher Structures in Geometry and Physics (Chapters 1-5 and 18-21); Winter of Disconnectedness (Chapter 6 and 22-26); Approximation and Optimisation (Chapters 7-8); Refining C*-Algebraic Invariants for Dynamics using KK-theory (Chapters 9-13); Interactions between Topological Recursion, Modularity, Quantum Invariants and Low-dimensional Topology (Chapters 14-17 and 27). The MATRIX Scientific Committee selected these programs based on their scientific excellence and the participation rate of high-profile international participants. Each program included ample unstructured time to encourage collaborative research; some of the longer programs also included an embedded conference or lecture series. The artic...
Energy Technology Data Exchange (ETDEWEB)
Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory
2010-01-01
In the matrix interdiction problem, a real-valued matrix and an integer k is given. The objective is to remove k columns such that the sum over all rows of the maximum entry in each row is minimized. This combinatorial problem is closely related to bipartite network interdiction problem which can be applied to prioritize the border checkpoints in order to minimize the probability that an adversary can successfully cross the border. After introducing the matrix interdiction problem, we will prove the problem is NP-hard, and even NP-hard to approximate with an additive n{gamma} factor for a fixed constant {gamma}. We also present an algorithm for this problem that achieves a factor of (n-k) mUltiplicative approximation ratio.
DEFF Research Database (Denmark)
Frandsen, Gudmund Skovbjerg; Frandsen, Peter Frands
2009-01-01
We consider maintaining information about the rank of a matrix under changes of the entries. For n×n matrices, we show an upper bound of O(n1.575) arithmetic operations and a lower bound of Ω(n) arithmetic operations per element change. The upper bound is valid when changing up to O(n0.575) entries...... in a single column of the matrix. We also give an algorithm that maintains the rank using O(n2) arithmetic operations per rank one update. These bounds appear to be the first nontrivial bounds for the problem. The upper bounds are valid for arbitrary fields, whereas the lower bound is valid for algebraically...... closed fields. The upper bound for element updates uses fast rectangular matrix multiplication, and the lower bound involves further development of an earlier technique for proving lower bounds for dynamic computation of rational functions....
Pérez López, César
2014-01-01
MATLAB is a high-level language and environment for numerical computation, visualization, and programming. Using MATLAB, you can analyze data, develop algorithms, and create models and applications. The language, tools, and built-in math functions enable you to explore multiple approaches and reach a solution faster than with spreadsheets or traditional programming languages, such as C/C++ or Java. MATLAB Matrix Algebra introduces you to the MATLAB language with practical hands-on instructions and results, allowing you to quickly achieve your goals. Starting with a look at symbolic and numeric variables, with an emphasis on vector and matrix variables, you will go on to examine functions and operations that support vectors and matrices as arguments, including those based on analytic parent functions. Computational methods for finding eigenvalues and eigenvectors of matrices are detailed, leading to various matrix decompositions. Applications such as change of bases, the classification of quadratic forms and ...
Hohn, Franz E
2012-01-01
This complete and coherent exposition, complemented by numerous illustrative examples, offers readers a text that can teach by itself. Fully rigorous in its treatment, it offers a mathematically sound sequencing of topics. The work starts with the most basic laws of matrix algebra and progresses to the sweep-out process for obtaining the complete solution of any given system of linear equations - homogeneous or nonhomogeneous - and the role of matrix algebra in the presentation of useful geometric ideas, techniques, and terminology.Other subjects include the complete treatment of the structur
International Nuclear Information System (INIS)
Brown, T.W.
2010-11-01
The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Brown, T.W.
2010-11-15
The same complex matrix model calculates both tachyon scattering for the c=1 non-critical string at the self-dual radius and certain correlation functions of half-BPS operators in N=4 super- Yang-Mills. It is dual to another complex matrix model where the couplings of the first model are encoded in the Kontsevich-like variables of the second. The duality between the theories is mirrored by the duality of their Feynman diagrams. Analogously to the Hermitian Kontsevich- Penner model, the correlation functions of the second model can be written as sums over discrete points in subspaces of the moduli space of punctured Riemann surfaces. (orig.)
Space Tourism: Orbital Debris Considerations
Mahmoudian, N.; Shajiee, S.; Moghani, T.; Bahrami, M.
2002-01-01
Space activities after a phase of research and development, political competition and national prestige have entered an era of real commercialization. Remote sensing, earth observation, and communication are among the areas in which this growing industry is facing competition and declining government money. A project like International Space Station, which draws from public money, has not only opened a window of real multinational cooperation, but also changed space travel from a mere fantasy into a real world activity. Besides research activities for sending man to moon and Mars and other outer planets, space travel has attracted a considerable attention in recent years in the form of space tourism. Four countries from space fairing nations are actively involved in the development of space tourism. Even, nations which are either in early stages of space technology development or just beginning their space activities, have high ambitions in this area. This is worth noting considering their limited resources. At present, trips to space are available, but limited and expensive. To move beyond this point to generally available trips to orbit and week long stays in LEO, in orbital hotels, some of the required basic transportations, living requirements, and technological developments required for long stay in orbit are already underway. For tourism to develop to a real everyday business, not only the price has to come down to meaningful levels, but also safety considerations should be fully developed to attract travelers' trust. A serious hazard to space activities in general and space tourism in particular is space debris in earth orbit. Orbiting debris are man-made objects left over by space operations, hazardous to space missions. Since the higher density of debris population occurs in low earth orbit, which is also the same orbit of interest to space tourism, a careful attention should be paid to the effect of debris on tourism activities. In this study, after a
Angles-only relative orbit determination in low earth orbit
Ardaens, Jean-Sébastien; Gaias, Gabriella
2018-06-01
The paper provides an overview of the angles-only relative orbit determination activities conducted to support the Autonomous Vision Approach Navigation and Target Identification (AVANTI) experiment. This in-orbit endeavor was carried out by the German Space Operations Center (DLR/GSOC) in autumn 2016 to demonstrate the capability to perform spaceborne autonomous close-proximity operations using solely line-of-sight measurements. The images collected onboard have been reprocessed by an independent on-ground facility for precise relative orbit determination, which served as ultimate instance to monitor the formation safety and to characterize the onboard navigation and control performances. During two months, several rendezvous have been executed, generating a valuable collection of images taken at distances ranging from 50 km to only 50 m. Despite challenging experimental conditions characterized by a poor visibility and strong orbit perturbations, angles-only relative positioning products could be continuously derived throughout the whole experiment timeline, promising accuracy at the meter level during the close approaches. The results presented in the paper are complemented with former angles-only experience gained with the PRISMA satellites to better highlight the specificities induced by different orbits and satellite designs.
An Orbit Propagation Software for Mars Orbiting Spacecraft
Directory of Open Access Journals (Sweden)
Young-Joo Song
2004-12-01
Full Text Available An orbit propagation software for the Mars orbiting spacecraft has been developed and verified in preparations for the future Korean Mars missions. Dynamic model for Mars orbiting spacecraft has been studied, and Mars centered coordinate systems are utilized to express spacecraft state vectors. Coordinate corrections to the Mars centered coordinate system have been made to adjust the effects caused by Mars precession and nutation. After spacecraft enters Sphere of Influence (SOI of the Mars, the spacecraft experiences various perturbation effects as it approaches to Mars. Every possible perturbation effect is considered during integrations of spacecraft state vectors. The Mars50c gravity field model and the Mars-GRAM 2001 model are used to compute perturbation effects due to Mars gravity field and Mars atmospheric drag, respectively. To compute exact locations of other planets, JPL's DE405 ephemerides are used. Phobos and Deimos's ephemeris are computed using analytical method because their informations are not released with DE405. Mars Global Surveyor's mapping orbital data are used to verify the developed propagator performances. After one Martian day propagation (12 orbital periods, the results show about maximum ±5 meter errors, in every position state components(radial, cross-track and along-track, when compared to these from the Astrogator propagation in the Satellite Tool Kit. This result shows high reliability of the developed software which can be used to design near Mars missions for Korea, in future.
Using matrix organization to manage health care delivery organizations.
Allcorn, S
1990-01-01
Matrix organization can provide health care organization managers enhanced information processing, faster response times, and more flexibility to cope with greater organization complexity and rapidly changing operating environments. A review of the literature informed by work experience reveals that the use of matrix organization creates hard-to-manage ambiguity and balances of power in addition to providing positive benefits for health care organization managers. Solutions to matrix operating problems generally rely on the use of superior information and decision support systems and extensive staff training to develop attitudes and behavior consistent with the more collegial matrix organization culture. Further improvement in understanding the suitability of matrix organization for managing health care delivery organizations will involve appreciating the impact of partial implementation of matrix organization, temporary versus permanent uses of matrix organization, and the impact of the ambiguity created by dual lines of authority upon the exercise of power and authority.
Mepham, B.; Kaiser, M.; Thorstensen, E.; Tomkins, S.; Millar, K.
2006-01-01
The ethical matrix is a conceptual tool designed to help decision-makers (as individuals or working in groups) reach sound judgements or decisions about the ethical acceptability and/or optimal regulatory controls for existing or prospective technologies in the field of food and agriculture.
Mitjana, Margarida
2018-01-01
This book contains the notes of the lectures delivered at an Advanced Course on Combinatorial Matrix Theory held at Centre de Recerca Matemàtica (CRM) in Barcelona. These notes correspond to five series of lectures. The first series is dedicated to the study of several matrix classes defined combinatorially, and was delivered by Richard A. Brualdi. The second one, given by Pauline van den Driessche, is concerned with the study of spectral properties of matrices with a given sign pattern. Dragan Stevanović delivered the third one, devoted to describing the spectral radius of a graph as a tool to provide bounds of parameters related with properties of a graph. The fourth lecture was delivered by Stephen Kirkland and is dedicated to the applications of the Group Inverse of the Laplacian matrix. The last one, given by Ángeles Carmona, focuses on boundary value problems on finite networks with special in-depth on the M-matrix inverse problem.
Visualizing Matrix Multiplication
Daugulis, Peteris; Sondore, Anita
2018-01-01
Efficient visualizations of computational algorithms are important tools for students, educators, and researchers. In this article, we point out an innovative visualization technique for matrix multiplication. This method differs from the standard, formal approach by using block matrices to make computations more visual. We find this method a…
DEFF Research Database (Denmark)
Jørnø, Rasmus Leth Vergmann; Gynther, Karsten; Christensen, Ove
2014-01-01
useful information, we question whether the axis of time and space comprising the matrix pertains to relevant defining properties of the tools, technology or learning environments to which they are applied. Subsequently we offer an example of an Adobe Connect e-learning session as an illustration...
CELLULAR CONTROL OF CONNECTIVE TISSUE MATRIX TENSION†
Langevin, Helene M.; Nedergaard, Maiken; Howe, Alan
2013-01-01
The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occurs during viscoelastic relaxation. We propose that this response of fibroblasts plays a role in regulating extracellular fluid flow into the tissue, and protects against swelling when the matrix is stretched. This article reviews the evidence supporting possible mechanisms underlying this response including autocrine purinergic signaling. We also discuss fibroblast regulation of connective tissue tension with respect to lymphatic flow, immune function and cancer. PMID:23444198
Cellular control of connective tissue matrix tension.
Langevin, Helene M; Nedergaard, Maiken; Howe, Alan K
2013-08-01
The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occurs during viscoelastic relaxation. We propose that this response of fibroblasts plays a role in regulating extracellular fluid flow into the tissue, and protects against swelling when the matrix is stretched. This article reviews the evidence supporting possible mechanisms underlying this response including autocrine purinergic signaling. We also discuss fibroblast regulation of connective tissue tension with respect to lymphatic flow, immune function, and cancer. Copyright © 2013 Wiley Periodicals, Inc.
Fibre-Matrix Interaction in Soft Tissue
International Nuclear Information System (INIS)
Guo, Zaoyang
2010-01-01
Although the mechanical behaviour of soft tissue has been extensively studied, the interaction between the collagen fibres and the ground matrix has not been well understood and is therefore ignored by most constitutive models of soft tissue. In this paper, the human annulus fibrosus is used as an example and the potential fibre-matrix interaction is identified by careful investigation of the experimental results of biaxial and uniaxial testing of the human annulus fibrosus. First, the uniaxial testing result of the HAF along the axial direction is analysed and it is shown that the mechanical behaviour of the ground matrix can be well simulated by the incompressible neo-Hookean model when the collagen fibres are all under contraction. If the collagen fibres are stretched, the response of the ground matrix can still be described by the incompressible neo-Hookean model, but the effective stiffness of the matrix depends on the fibre stretch ratio. This stiffness can be more than 10 times larger than the one obtained with collagen fibres under contraction. This phenomenon can only be explained by the fibre-matrix interaction. Furthermore, we find that the physical interpretation of this interaction includes the inhomogeneity of the soft tissue and the fibre orientation dispersion. The dependence of the tangent stiffness of the matrix on the first invariant of the deformation tensor can also be explained by the fibre orientation dispersion. The significant effect of the fibre-matrix interaction strain energy on mechanical behaviour of the soft tissue is also illustrated by comparing some simulation results.
Effects of Colored Noise on Periodic Orbits in a One-Dimensional Map
Li, Feng-Guo; Ai, Bao-Quan
2011-06-01
Noise can induce inverse period-doubling transition and chaos. The effects of the colored noise on periodic orbits, of the different periodic sequences in the logistic map, are investigated. It is found that the dynamical behaviors of the orbits, induced by an exponentially correlated colored noise, are different in the mergence of transition, and the effects of the noise intensity on their dynamical behaviors are different from the effects of the correlation time of noise. Remarkably, the noise can induce new periodic orbits, namely, two new orbits emerge in the period-four sequence at the bifurcation parameter value μ = 3.5, four new orbits in the period-eight sequence at μ = 3.55, and three new orbits in the period-six sequence at μ = 3.846, respectively. Moreover, the dynamical behaviors of the new orbits clearly show the resonancelike response to the colored noise.
Effects of Colored Noise on Periodic Orbits in a One-Dimensional Map
International Nuclear Information System (INIS)
Li Fengguo; Ai Baoquan
2011-01-01
Noise can induce inverse period-doubling transition and chaos. The effects of the colored noise on periodic orbits, of the different periodic sequences in the logistic map, are investigated. It is found that the dynamical behaviors of the orbits, induced by an exponentially correlated colored noise, are different in the mergence of transition, and the effects of the noise intensity on their dynamical behaviors are different from the effects of the correlation time of noise. Remarkably, the noise can induce new periodic orbits, namely, two new orbits emerge in the period-four sequence at the bifurcation parameter value μ = 3.5, four new orbits in the period-eight sequence at μ = 3.55, and three new orbits in the period-six sequence at μ = 3.846, respectively. Moreover, the dynamical behaviors of the new orbits clearly show the resonancelike response to the colored noise. (general)
CELLULAR CONTROL OF CONNECTIVE TISSUE MATRIX TENSION†
Langevin, Helene M.; Nedergaard, Maiken; Howe, Alan
2013-01-01
The biomechanical behavior of connective tissue in response to stretching is generally attributed to the molecular composition and organization of its extracellular matrix. It also is becoming apparent that fibroblasts play an active role in regulating connective tissue tension. In response to static stretching of the tissue, fibroblasts expand within minutes by actively remodeling their cytoskeleton. This dynamic change in fibroblast shape contributes to the drop in tissue tension that occur...
The Eccentric Behavior of Nearly Frozen Orbits
Sweetser, Theodore H.; Vincent, Mark A.
2013-01-01
Frozen orbits are orbits which have only short-period changes in their mean eccentricity and argument of periapse, so that they basically keep a fixed orientation within their plane of motion. Nearly frozen orbits are those whose eccentricity and argument of periapse have values close to those of a frozen orbit. We call them "nearly" frozen because their eccentricity vector (a vector whose polar coordinates are eccentricity and argument of periapse) will stay within a bounded distance from the frozen orbit eccentricity vector, circulating around it over time. For highly inclined orbits around the Earth, this distance is effectively constant over time. Furthermore, frozen orbit eccentricity values are low enough that these orbits are essentially eccentric (i.e., off center) circles, so that nearly frozen orbits around Earth are bounded above and below by frozen orbits.
The method of coadjoint orbits
International Nuclear Information System (INIS)
Delius, G.W.; Van Nieuwenhuizen, P.; Rodgers, V.G.J.
1990-01-01
The method of coadjoint orbits produces for any infinite dimensional Lie (super) algebra A with nontrivial central charge an action for scalar (super) fields which has at least the symmetry A. In this article, the authors try to make this method accessible to a larger audience by analyzing several examples in more detail than in the literature. After working through the Kac-Moody and Virasoro cases, we apply the method to the super Virasoro algebra and reobtain the super-symmetric extension of Polyakov's local nonpolynomial action for two-dimensional quantum gravity. As in the Virasoro case this action corresponds to the coadjoint orbit of a pure central extension. The authors further consider the actions corresponding to the other orbits of the super Virasoro algebra. As a new result the authors construct the actions for the N = 2 super Virasoro algebra
Gravity Probe B orbit determination
International Nuclear Information System (INIS)
Shestople, P; Ndili, A; Parkinson, B W; Small, H; Hanuschak, G
2015-01-01
The Gravity Probe B (GP-B) satellite was equipped with a pair of redundant Global Positioning System (GPS) receivers used to provide navigation solutions for real-time and post-processed orbit determination (OD), as well as to establish the relation between vehicle time and coordinated universal time. The receivers performed better than the real-time position requirement of 100 m rms per axis. Post-processed solutions indicated an rms position error of 2.5 m and an rms velocity error of 2.2 mm s −1 . Satellite laser ranging measurements provided independent verification of the GPS-derived GP-B orbit. We discuss the modifications and performance of the Trimble Advance Navigation System Vector III GPS receivers. We describe the GP-B precision orbit and detail the OD methodology, including ephemeris errors and the laser ranging measurements. (paper)
MRI of orbital hydroxyapatite implants
International Nuclear Information System (INIS)
Flanders, A.E.; De Potter P.; Rao, V.M.; Tom, B.M.; Shields, C.L.; Shields, J.A.
1996-01-01
Our aim was to use MRI for the postsurgical assessment of a new form of integrated orbital implant composed of a porous calcium phosphate hydroxyapatite substrate. We studied ten patients 24-74 years of age who underwent enucleation and implantation of a hydroxyapatite ball; 5-13 months after surgery, each patient was examined by spin-echo MRI, with fat suppression and gadolinium enhancement. Fibrovascular ingrowth was demonstrated in all ten patients as areas of enhancement at the periphery of the hydroxyapatite sphere that extended to the center to a variable degree. The radiologist should aware of the MRI appearances of the coralline hydroxyapatite orbital implant since it is now widely used following enucleation. MRI is a useful means to determine successful incorporation of the substrate into the orbital tissues. The normal pattern of contrast enhancement should not be mistaken for recurrent tumor or infection. (orig.)
Schröer, H.
Orbits of small balls on revolutions solid shells are examined. Which velocity is necessary to stay in balance? The angular velocity remains constant. General revolution solid, revolution cone, revolution ellipsoid, ball, paraboloid and hyperboloid are treated. Chapter 1 represents the frictionless case. Chapter 2 deals with the friction case. The transformation from velocity to the belonging orbit height is calculated in chapter 3. In chapter 4 and 5 the macro revolution solids follow (without and with friction)is treated. The assumption of a homogeneous field is not possible here. The radial gravitational field must be used. In the last chapter we have orbits with non constant angular velocity that can be derived with the Lagrange-equations of the second kind in the frictionless case. Here is also possible to view different revolution solids. The book is recommended to all experimental-, theoretical and mathematical physicists. There is an english and a german edition.
Orbital periods of recurrent novae
International Nuclear Information System (INIS)
Schaefer, B.E.
1990-01-01
The class of recurrent novae (RN) with thermonuclear runaways contains only three systems (T Pyx, U Sco, and V394 CrA), for which no orbital periods are known. This paper presents a series of photometric observations where the orbital periods for all three systems are discovered. T Pyx is found to have sinusoidal modulation with an amplitude of 0.08 mag and a period of 2.3783 h (with a possible alias of 2.6403 h). U Sco is found to be an eclipsing system with an eclipse amplitude of roughly 1.5 mag and an orbital period of 1.2344 days. V394 CrA is found to have sinusoidal modulation with an amplitude of 0.5 mag and a period of 0.7577 days. Thus two out of three RN with thermonuclear runaways (or five out of six for all RN) have evolved companions. 16 refs
Energy Technology Data Exchange (ETDEWEB)
Yamashita, Yasuyuki; Sato, Ryuiti; Sakamoto, Yuji; Kojima, Ryutaro; Takahashi, Mutsumasa; Maruoka, Syouko; Okamura, Ryoichi; Oguni, Tatsuro.
1989-05-01
Sixty five cases with orbital and ocular lesions were evaluated by MRI in comparison with high resolution CT. MRI was performed with spin echo techniques (short TR/TE and long TR/TE) using a 0.22 tesla resistive unit (Toshiba MRT-22A) or a 1.5 tesla superconductive unit (Siemens Magnetom). MRI was superior to CT in (1) detecting ocular lesions and vitreous changes, (2) differentiating a tumor from the adjacent extraocular muscles and optic nerves, (3) identifying the lesion in the orbital apex and demonstrating the posterior extent of the tumor and (4) detecting the abnormal flow in the orbital vascular structures. Although some tumors had specific signal intensities including hemangioma, menigioma, and pseudotumor, majority of tumors revealed non-sepcific signal intensities. CT was superior to MRI in detection for small and calcified lesions as well as visualization of bone details. (author).
Orbital computed tomography for exophthalmos
International Nuclear Information System (INIS)
Kim, Ok Keun; Lee, Hyun; Sol, Chang Hyo; Kim, Byung Soo
1987-01-01
Since exophthalmos is caused by any decrease in the size of bony orbit or occurrence of mass within the rigid orbit, the accurate diagnosis of its causes are essential in determining the therapeutic aims. Exophthalmos is one of the important signs being the indication for orbital computed tomography along with periorbital swelling, visual loss, orbital trauma and diplopia. CT as the diagnostic tool for the cause of exophthalmos not only displays a superb role with uncomparable quality in comparison to any conventional diagnostic methods but also has a decisive role in determining the therapeutic aims and the appropriate operative method when the operation is indicated. The orbital CT was performed from May in 1983 to May in 1985 whose with chief complaints were exophthalmos and 23 cases were confirmed by operation, biopsy, clinical progression or other diagnostic procedures. Here was report thoroughly analyzed 23 cases. The results were as follows : 1. The etiologic disease of exophthalmos were 6 cases of pseudotumor, 4 cases of thyroid ophthalmopathy, 4 cases of maxill ary sinus and nasal cavity Ca., 3 cases of mucocele and 1 case of alveolar soft part sarcoma, osteoma, dermoid cyst, pleomorphic adenoma, meningioma, and C.C.F. each. 2. The origin of the etiologic diseases of exophthalmos were 13 cases of primary within bony orbit and 10 cases of secondary from adjacent structure. 3. The site of lesions were 11 cases of intraconal and extraconal, 10 cases of extraconal, and 2 cases of intraconal origin. 4. The degree of exophthalmos in CT scan was in proportion to the volume of the mass except in the case of thyroid ophthalmopathy. The upper limit of normal range by CT scan using regression line equation was 16.2 mm in approximation. 5. CT was a very useful diagnostic tool in the accurate assessment of the kinds of lesion, its location, and its relationship to adjacent structures in the diagnosis of etiologic diseases of exophthalmos
Orbital computed tomography for exophthalmos
Energy Technology Data Exchange (ETDEWEB)
Kim, Ok Keun; Lee, Hyun; Sol, Chang Hyo; Kim, Byung Soo [College of Medicine, Pusan National University, Busan (Korea, Republic of)
1987-06-15
Since exophthalmos is caused by any decrease in the size of bony orbit or occurrence of mass within the rigid orbit, the accurate diagnosis of its causes are essential in determining the therapeutic aims. Exophthalmos is one of the important signs being the indication for orbital computed tomography along with periorbital swelling, visual loss, orbital trauma and diplopia. CT as the diagnostic tool for the cause of exophthalmos not only displays a superb role with uncomparable quality in comparison to any conventional diagnostic methods but also has a decisive role in determining the therapeutic aims and the appropriate operative method when the operation is indicated. The orbital CT was performed from May in 1983 to May in 1985 whose with chief complaints were exophthalmos and 23 cases were confirmed by operation, biopsy, clinical progression or other diagnostic procedures. Here was report thoroughly analyzed 23 cases. The results were as follows : 1. The etiologic disease of exophthalmos were 6 cases of pseudotumor, 4 cases of thyroid ophthalmopathy, 4 cases of maxill ary sinus and nasal cavity Ca., 3 cases of mucocele and 1 case of alveolar soft part sarcoma, osteoma, dermoid cyst, pleomorphic adenoma, meningioma, and C.C.F. each. 2. The origin of the etiologic diseases of exophthalmos were 13 cases of primary within bony orbit and 10 cases of secondary from adjacent structure. 3. The site of lesions were 11 cases of intraconal and extraconal, 10 cases of extraconal, and 2 cases of intraconal origin. 4. The degree of exophthalmos in CT scan was in proportion to the volume of the mass except in the case of thyroid ophthalmopathy. The upper limit of normal range by CT scan using regression line equation was 16.2 mm in approximation. 5. CT was a very useful diagnostic tool in the accurate assessment of the kinds of lesion, its location, and its relationship to adjacent structures in the diagnosis of etiologic diseases of exophthalmos.
Robust Tracking Control for Rendezvous in Near-Circular Orbits
Directory of Open Access Journals (Sweden)
Neng Wan
2013-01-01
Full Text Available This paper investigates a robust guaranteed cost tracking control problem for thrust-limited spacecraft rendezvous in near-circular orbits. Relative motion model is established based on the two-body problem with noncircularity of the target orbit described as a parameter uncertainty. A guaranteed cost tracking controller with input saturation is designed via a linear matrix inequality (LMI method, and sufficient conditions for the existence of the robust tracking controller are derived, which is more concise and less conservative compared with the previous works. Numerical examples are provided for both time-invariant and time-variant reference signals to illustrate the effectiveness of the proposed control scheme when applied to the terminal rendezvous and other astronautic missions with scheduled states signal.
GLONASS orbit/clock combination in VNIIFTRI
Bezmenov, I.; Pasynok, S.
2015-08-01
An algorithm and a program for GLONASS satellites orbit/clock combination based on daily precise orbits submitted by several Analytic Centers were developed. Some theoretical estimates for combine orbit positions RMS were derived. It was shown that under condition that RMS of satellite orbits provided by the Analytic Centers during a long time interval are commensurable the RMS of combine orbit positions is no greater than RMS of other satellite positions estimated by any of the Analytic Centers.
Precise GPS orbits for geodesy
Colombo, Oscar L.
1994-01-01
The Global Positioning System (GPS) has become, in recent years, the main space-based system for surveying and navigation in many military, commercial, cadastral, mapping, and scientific applications. Better receivers, interferometric techniques (DGPS), and advances in post-processing methods have made possible to position fixed or moving receivers with sub-decimeter accuracies in a global reference frame. Improved methods for obtaining the orbits of the GPS satellites have played a major role in these achievements; this paper gives a personal view of the main developments in GPS orbit determination.
Primary orbital squamous cell carcinoma
Directory of Open Access Journals (Sweden)
Ana L. Campos Arbulú
2017-02-01
Full Text Available Primary orbital squamous cell carcinoma is a rare entity. There is little published literature. We report a case of primary squamous cell carcinoma of the orbital soft tissues. Surgical resection offered the best treatment for the patient. Complete resection of the lesion was achieved. The patient received adjuvant radiotherapy due to the proximity of the lesion to the surgical margins. Surgical treatment is feasible and should be considered as part of the surgeon's arsenal. However, therapeutic decisions must be made on a case-by-case basis
Orbital resonances around black holes.
Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja
2015-02-27
We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here.
Orbital effects in actinide systems
International Nuclear Information System (INIS)
Lander, G.H.
1983-01-01
Actinide magnetism presents a number of important challenges; in particular, the proximity of 5f band to the Fermi energy gives rise to strong interaction with both d and s like conduction electrons, and the extended nature of the 5f electrons means that they can interact with electron orbitals from neighboring atoms. Theory has recently addressed these problems. Often neglected, however, is the overwhelming evidence for large orbital contributions to the magnetic properties of actinides. Some experimental evidence for these effects are presented briefly in this paper. They point, clearly incorrectly, to a very localized picture for the 5f electrons. This dichotomy only enhances the nature of the challenge
AA, closed orbit observation pickup
1980-01-01
Electrostatic pickups around the circumference of the AA served for the measurement of the closed orbits across the wide momentum range of +- 3% to either side of central orbit. The pickups were of the "shoebox" type, with diagonal cuts, a horizontal and a vertical one mechanically coupled together. They were located where they would not require extra space. The small ones, like the one we see here, were inserted into the vacuum chamber of the BLG (long and narrow) bending magnets. See also 8001372, 8010042, 8010045
AA, closed orbit observation pickup
CERN PhotoLab
1980-01-01
Electrostatic pickups around the circumference of the AA served for the measurement of the closed orbits across the wide momentum range of +- 3% to either side of central orbit. The pickups were of the "shoebox" type, with diagonal cuts, a horizontal and a vertical one mechanically coupled together. They were located where they would not require extra space. The wide ones (very wide indeed: 70 cm), like the one we see here, were placed inside the vacuum chamber of the wide quadrupoles QFW, at maximum dispersion. See also 8001372, 8001383, 8010045
AA, closed orbit observation pickup
CERN PhotoLab
1980-01-01
Electrostatic pickups around the circumference of the AA served for the measurement of the closed orbits across the wide momentum range of +- 3% to either side of central orbit. The pickups were of the "shoebox" type, with diagonal cuts, a horizontal and a vertical one mechanically coupled together. They were located where they would not require extra space. The wide ones (very wide indeed: 70 cm), like the one we see here, were placed inside the vacuum chamber of the wide quadrupoles, QFW, at maximum dispersion. See also 8001372,8001383, 8010042
AA, closed orbit observation pickup
CERN PhotoLab
1980-01-01
Electrostatic pickups around the circumference of the AA served for the measurement of the closed orbits across the wide momentum range of +- 3% to either side of central orbit. The pickups were of the "shoebox" type, with diagonal cuts, a horizontal and a vertical one mechanically coupled together. They were located where they would not require extra space. The small ones, like the one we see here, were inserted into the vacuum chamber of the BLG (long and narrow) bending magnets. Werner Sax contemplates his achievement. See also 8001383, 8010042, 8010045.
Energy and the Elliptical Orbit
Nettles, Bill
2009-03-01
In the January 2007 issue of The Physics Teacher, Prentis, Fulton, Hesse, and Mazzino describe a laboratory exercise in which students use a geometrical analysis inspired by Newton to show that an elliptical orbit and an inverse-square law force go hand in hand. The historical, geometrical, and teamwork aspects of the exercise are useful and important. This paper presents an exercise which uses an energy/angular momentum conservation model for elliptical orbits. This exercise can be done easily by an individual student and on regular notebook-sized paper.
Yokoyama, T.; Eto, M.; Nazarov, Y.V.
2012-01-01
We theoretically study the current-phase relation in semiconductor nanowire Josephson junction in the presence of spin-orbit interaction. In the nanowire, the impurity scattering with strong SO interaction is taken into account using the random matrix theory. In the absence of magnetic field, the
Assessment of Matrix Metalloproteinases by Gelatin Zymography.
Cathcart, Jillian
2016-01-01
Matrix metalloproteinases are endopeptidases responsible for remodeling of the extracellular matrix and have been identified as critical contributors to breast cancer progression. Gelatin zymography is a valuable tool which allows the analysis of MMP expression. In this approach, enzymes are resolved electrophoretically on a sodium dodecyl sulfate-polyacrylamide gel copolymerized with the substrate for the MMP of interest. Post electrophoresis, the enzymes are refolded in order for proteolysis of the incorporated substrate to occur. This assay yields valuable information about MMP isoforms or changes in activation and can be used to analyze the role of MMPs in normal versus pathological conditions.
The effect of chronic periodontitis on serum levels of matrix ...
African Journals Online (AJOL)
A complex network of chemokines and pro- and anti-inflammatory mediators is involved in the initiation and progression of chronic periodontitis. Matrix metalloproteinases (MMPs), the main enzymes responsible for matrix degradation, are important for periodontal tissue destruction, but their activity can be inhibited by tissue ...
Qian, Weixian; Zhou, Xiaojun; Lu, Yingcheng; Xu, Jiang
2015-09-15
Both the Jones and Mueller matrices encounter difficulties when physically modeling mixed materials or rough surfaces due to the complexity of light-matter interactions. To address these issues, we derived a matrix called the paths correlation matrix (PCM), which is a probabilistic mixture of Jones matrices of every light propagation path. Because PCM is related to actual light propagation paths, it is well suited for physical modeling. Experiments were performed, and the reflection PCM of a mixture of polypropylene and graphite was measured. The PCM of the mixed sample was accurately decomposed into pure polypropylene's single reflection, pure graphite's single reflection, and depolarization caused by multiple reflections, which is consistent with the theoretical derivation. Reflection parameters of rough surface can be calculated from PCM decomposition, and the results fit well with the theoretical calculations provided by the Fresnel equations. These theoretical and experimental analyses verify that PCM is an efficient way to physically model light-matter interactions.
International Nuclear Information System (INIS)
Sasakawa, T.; Okuno, H.; Ishikawa, S.; Sawada, T.
1982-01-01
The off-shell t matrix is expressed as a sum of one nonseparable and one separable terms so that it is useful for applications to more-than-two body problems. All poles are involved in this one separable term. Both the nonseparable and the separable terms of the kernel G 0 t are regular at the origin. The nonseparable term of this kernel vanishes at large distances, while the separable term behaves asymptotically as the spherical Hankel function. These properties make our expression free from defects inherent in the Jost or the K-matrix expressions, and many applications are anticipated. As the application, a compact expression of the many-level formula is presented. Also the application is suggested to the breakup threebody problem based on the Faddeev equation. It is demonstrated that the breakup amplitude is expressed in a simple and physically interesting form and we can calculate it in coordinate space